Android dual SIM handsets - recommendations and reviews
 

Hello world,

I'd been interested in buying a dual SIM Android handset for quite a while but since most of them were of low quality or had subpar specs, I hesitated until recently when I ordered a Zopo C2/ZP980 (32GB ROM/2GB RAM version).
The only downside of the Zopo C2/ZP980 for me is its UMTS support which is limited to 850 and 2100MHz, a pretty pointless combination of frequencies as these occur together only in very few markets (afaik Australia, New Zealand, Thailand).

As you guys probably consider buying a dual SIM handset, too, here's my personal list of interesting devices:

• Zopo C2/ZP980
  The Zopo ZP980 and C2 share identical hardware, but the later comes with Alyiun OS, a Chinese fork-off of Android, preinstalled which makes it slightly cheaper due to subsidies
  + 5" 1080p IPS screen
  + MTK6589(T) quadcore CPU with up to 1.5 GHz (other versions come with 1.2 GHz)
  + up to 2GB RAM/32 GB ROM (other versions come with 1GB/16GB or 1GB/4GB)
  + microSD slot
  + neat iPhonish design
  + UMTS support for both SIM cards
  + changeable battery
  - limited UMTS frequencies and odd frequency combination (850 & 2100 MHz)
  
  
• Huawei G700
  + 5" 720p display
  + Cortex-A7 quadcore CPU
  + 2GB RAM
  + 8 or 16GB internal storage
  + microSD slot
  + changeable battery
  + high battery capacity (2150mAh)
  + cheap (~ € 240)
  - UMTS support only for SIM1
  - only dualband UMTS (900/2100 MHz)
  - only triband GSM support (900/1800/1900 MHz)
  
  
• ZTE Blade C V807
  + cheap (~ € 90)
  + changeable battery
  - no front-facing camera
  - no magnetometer (electronic compass)
  - only dualband UMTS (900/2100 MHz)
  - only triband GSM support (900/1800/1900 MHz)
  - generally low specs
  
  
• Samsung Galaxy S4 Mini DuoS (I9192)
  + 4.3" qHD sAMOLED display
  + quadband UMTS support (850/900/1900/2100 MHz)
  + microSD slot
  + GLONASS support
  - expensive (~ € 380)
  - battery not changeable
  - low battery capacity (1900mAh)
  
  

I appreciate your thoughts and recommendations on these and further Android dual SIM handsets.

Cheers

I was not totally awake and read this:

• + MTK6589(T) hardcore CPU with up to 1.5 GHz (other versions come with 1.2 GHz)
  + chargeable battery
• Samsung
  + quadband UMTS support (850/900/1900/2100 MHz)

A chargeable battery, how nice.

The Samsung is the only one that has two US UMTS bands.

Perhaps they do not think dual-SIM is that marketable in the US.
This makes a start though.

I've heard pretty good things about the LG E455 Optimus L5 II Dual SIM. Quad band GSM and UMTS.

Details are sketchy on the LG site but I plan on taking a look at it next time I'm in Europe.

Price wise it should be about €170 VAT in.

I have this basic one and it has served me well. I have the 6102-B model. Samsung Galaxy Y Duos S6102 - Full phone specifications

Since the vast majority of phones in the US are sold through the carriers and the carriers have no interest in providing multiple-SIMs, you are probably correct.

I also have a Zopo (The ZP 100) and i am very content with the hardware quality. And the bands too as i ususally use it either in germany or in Thailand ;)

Chris

Unfortunately I was misinformed and in fact the Zopo C2/ZP980 supports UMTS only for the first SIM card. The second radio module supports only quadband GSM.

Brand name Dual Sim (only) available for chineese market
 

e.g. the HTC one Dual Sim for the chineese market offers also a µSD-Slot!

Strangely even though HTC is located in Taiwan, but I couldn't buy it in Taipee when I was there. The chineese market seems to be large enough for manufacterers to produce and limit products to/for china.

A final note on the Zopo C2/ZP980's dual SIM functionality:
Both SIM slots support UMTS but only alternately, so one of the SIMs will always be restricted to GSM. 3G assignment can be switched under
Settings > More... > Mobile networks > 3G service > Enable 3G > Select desired SIM

All other dual SIM-related settings can be found under Settings > SIM management where preferences for voice calls, video calls, SMS and data connections are being set. "Contact binding" allows specific phonebook items to be always called/texted through one of the SIMs.

'It's a feature and not a bug.'
 

Well, if you had not started this interesting thread you [and we]
would not have found out this important bit of info---and have prevented much sim-swapping.
Could this be seen as a battery-saving feature?
'It's a feature and not a bug.'

I've got a Samsung Galaxy S Duos S7562, but find it exceedingly limited. (It's not my main phone, thankfully - I generally much prefer Windows Phone, but there isn't a dual-SIM WP available yet.) It has only 4 MB of internal memory, of which less than half is available, but you can't store apps on the SD card. This makes it semi-useless for things like navigation. Only one SIM may use UMTS. And the phone makes it difficult to dial a number stored on one SIM using the other SIM. It's also relatively slow (single-core 1 GHz processor). But the camera is OK, and it can be sometimes had for around 130 euros.

The fact that only one radio module supports UMTS definitely saves battery life as UMTS - despite significantly lower transmission power levels (max. 0.25W vs. 1-2 for GSM) - requires a lot of CPU power for the spreading codes calculations which results in higher power consumption by the baseband processor. Besides impairing standby performance a second UMTS radio module would also increase hardware complexity and - most importantly - production and royality expenses. Further to that simultaneous UMTS support for the second SIM would also be quite pointless to most users as the most relevant advantage of UMTS is its higher data bandwidth but establishing a simultaneous second data session is useless. Instead most users will use the second SIM only for voice and SMS for which GSM still works fine as long as GSM and UMTS coverage are overlapping. However since there are UMTS-only networks without overlapping GSM coverage as a fallback option and since more and more operators are reducing GSM capacity by refarming former GSM spectrum in favour of UMTS or LTE deployments UMTS support for the second SIM is becoming a necessity.
Has anybody actually seen any dual SIM device with dual UMTS support yet?

Japan and S. Korea come to mind.

I have a Star W007 (for sale - see for sale on here).

It's to stop any signal conflicts - one SIM is on 3G, the other on 2G - means they can both have best signal reception/transmission conditions. If two 3G handsets are in close proximinity, the spread spectrum nature of the signals means you get a lot more bad packets.

It's a clever solution to the problem of using two 3G transceivers in close proximity.

The Star W007 is software-switchable in this regard - i.e. you can switch which transceiver module pairs with which SIM card.

+Steve :)

If it actually was a problem to establish two separate radio links on adjacent UMTS frequencies from the same handset how could DC-HSPA work which does just the same to increase bandwidth? Integrating two 3G radio modules may be a cost-related problem for budget phones but I think there's no major technical issue at all.
Also keep in mind that the 5 MHz channels of UMTS include guardbands of 580kHz at the upper and lower end. So the actual carrier bandwidth of a UMTS channel is only 3840kHz and all carriers are separated by 1160kHz which should suffice to avoid interferences.

DC-HSPA is - I think - only in Release 8 version at the moment Mr I - all is does is to double the data rates by doubling the bandwidth to 10 MHz (2×5 MHz).

In theory, DC-HSDPA can support up to 42.2 Mbps, but unlike HSPA, it does not need to rely on MIMO transmission. This is the key.

My understandng is that Release 8 of DC-HSDPA can only operate on adjacent carriers, whilst Release 9 will allow the paired cells to operate on two different frequency bands. I was talking to a Three tech recently who said the carrier is testing Quad Channel - QC-HSPA!

Obviously the spread spectrum nature of 3G / DC-HSPA in this context will result in packet quality degradation, but since it's one handset and one cell site controlling everything, it's not a MAJOR problem.

What I was trying to say - sorry I didn't express myself clearly - is that two 3G transceivers placed side by side would hit packet quality problems - and since we're talking about handsets that are designed cheaply and based on older chip sets, having one 3G and one 2G transceiver in the same handset avoids any problems - and it's cheaper :)

+Steve :)

I've been using the Sony Xperia Tipo ST21A2 as my primary phone for about 8 months now. I paid US$138 for it (~ € 100), new.

http://www.amazon.com/Sony-Dual-SIM-.../dp/B0093HKO2U

+ cheap (~ € 100)
+ changeable battery
+ quadband GSM
+ triband UMTS (850/1900/2100 MHz) (so no 900 3G for Europe)
(note: the ST21i2 has 900/2100 instead)
+ very good battery life
+ normal size mini sims
+ Android 4.0 ICS
+ microSD slot up to 32GB
+ standard micro-USB for charging
+ small
- small low-res screen
- no front-facing camera
- no magnetometer (electronic compass)
- poor camera with no autofocus
- touchscreen could be more responsive

Not a perfect phone, but for the price it's been very useful, especially with the battery lasting for days of travel. Like virtually all these phones, only one SIM can be on 3G at a time (but it can be either sim slot).

Having said that, I'm considering changing it. It's nice and small and light, but this means the screen is just a bit too small, harder to read and more difficult to touch in the right places. But as you know there's not much else out there, at a sensible price. Dual sims are very useful to me (quad sims would be great, I currently have a second plain GSM dual sim phone for the others).

Hello everybody. I just thought I would reawaken this oldish thread as my current multi-handset setup used to work perfectly well up until a few days ago when a rather unfortunate incident of a bottle breaking in my bag left one of those phones covered in rather nice brandy and rather dead! :(

Has anyone got any recent experiences with any half-decent dual-SIM or triple-SIM android phones?

In the dual-SIM world, I have been particularly looking at the Zopo C3 and how it weighs up against the C2 that Inquisitor has already reviewed above. I am not sure if it is worth the extra money though.

I still like the look of the Zopo C2 and see that it is currently around £168 = 200 Euros (e.g. http://www.amazon.co.uk/gp/product/B00FS99CT8) As far as I can tell, these now come with normal Android and not the Alyiun OS. However, it is a bit confusing as the title of that product suggests 1.2 Ghz quad processor and later in the spec it says 1.5. Then there is the Zopo C2 Platinum which costs a bit more and has same spec again.
So confused!

Upon reading more about Zopos I think their newest offering is actually the ZP998 which has a whopping 8 cores! I see it is available for around 219 Euros. http://chinamobilemag.com/zopo-zp998...tphone-review/ Interestingly, this one is confirmed to have 3G radio modules for both SIMs. I am sure the 8 cores are significantly helping with that.

The Moto G dual sim is not bad - http://www.amazon.com/gp/aw/d/B00I34...&robot_redir=1

Let me assure you the phone did not feel a thing.
Thanks for updating this thread.

@petkow
I have actually given away my Zopo C2 recently due to its very bad Wifi and GPS sensitivity about which I reported a while back on another forum: http://forum.zopomobileshop.com/thread-1314-1-1.html (note this post showing internal photos)

Though my device probably showed exceptionally bad performance you should be aware that besides serial dispersion resulting from wide quality tolerances at Zopo they use quite primitive monopole antennae for Wifi, GPS and BT instead of sophisticated duopole ones. You will not necessarily need to wait 5 minutes to acquire a satfix under a clear obstacle-free sky like I had to, but expect a Zopo to underperform quality brands. Further shortcomings of Zopo are that there's no 5GHz Wifi support and so far none of their phones supports GLONASS which could dramatically improve TTFF as well as accuracy.

In any case you should better order your device from a seller in your country so you can return it hassle-free, should you experience similar issues.

Regarding the ZP998 another advantage over the ZP980/C2 is that it supports UMTS on 900/1900/2100MHz, while the ZP990/C2 comes with the rather useless 850/2100MHz combination (at least for Europeans). Though I doubt that the ZP998 actually supports 3G for both SIM cards simultaneously, as you say. Instead it would rather have the ability to assign the 3G-capable radio module to any of the SIMs from the menu like I described it in post #9 of this thread.

Yes... the Moto G is a great phone for the little money it costs...The funny thing is that is exactly what my network offered me as a replacement for my brandy inebriated phone! Unfortunately the networks here in Europe will never give you a dual SIM handset hence why I need to buy one outright.

Thanks. It looks like I will not touch that phone with a barge-pole then. I did read about problems with the GPS elsewhere too and someone struggling to pick up many satellites.

I am very interested in this phone, but perhaps it is a lot to be paying for a dubious brand. Also I am not sure I really need 8 cores, as not very many apps exist that can really make use of them. I am not much of a hard-core gamer! None the less, it seems a good phone with good reviews.

Though you are right that I should try and buy it at a local dealer, I saw it available on e-fox at a very attractive price but to be honest their prices confuse me. I have never used that site and was wondering if you or anyone has experience with them? I think they also ship to Spain. Why is the same phone listed twice at two different prices
here and here ?? Is that difference just the delivery charge?

I have also been looking at the other end of the spectrum and thinking about picking up something cheap and cheerful. (you never know where my bottle breaking luck takes me). I see that e-fox is selling the CUBOT P9 dual SIM for only 65 euros today! Anyone know anything about this phone?

:drunk: What a way to go. ;) What about the brandy? Were you able to salvage any of it? A doubly cruel loss. :sad:

There are complaints about bad GPS reception for the ZP998, too.

The first one comes from China while the later and more expensive one is being dispatched from Germany ("versandkosten frei aus DE" = "free shipping from Germany"). Actually in the cheaper offer there's a button labeled "aus DE versendet kaufen" ("buy dispatched from Germany") which takes you to the later item.

Never got my hands on that one but 512MB RAM would be a showstopper for me and I don't see any point in accepting the bulkiness of a 5" display when it comes with such a low resoution (540*960px) unless you are visually impaired.
If I was to buy a dual SIM handset again, I would definitely consider the Samsung Galaxy Grand 2 DuoS (G7102) which supports 5GHz Wifi, GLONASS and quadband UMTS (850/900/1900/2100) and is made in Samsung's typical high build quality.
By the way, I think FullHD (1920*1080px) is totally pointless on a 5" screen as the increased pixel density over 1280*720px is far from any human eye's visual capabilites (at least if you hold the device in a usual distance from your eye of a foot or so) and so it is a total waste of resources to produce these displays which then require exponentially more CPU/GPU power to render the higher resolution frames and so impair battery life. Indeed I could not really take notice when downgrading from a 1920*1080px@5" screen to 1280*720px@4.7". But 960*540 is definitely too little for a 5" device.

P.S.: Next time just pour the brandy from the bottle into your stomache, so it can't flood your phone anymore. However this may entail some new risks for your handset.

Slightly OT, but Nokia is readying a dual-SIM Windows Phone, the Lumia 630. This is an entry-level model, but (speaking as a WP user) I'd expect the experience to be quite a lot nicer than with cheap Android phones.

http://www.engadget.com/2014/04/02/n...-635-hands-on/

Thanks so much to inquisitor and other others for your helpful reviews and suggestions! To be honest I was not considering the Cubot P9 as a serious day-to-day contender, but a workable rugged travel phone, useful for taking to the beach and if it got drowned or found itself in a bag with other toxic substances.. then it would not be the end of the world! Although you are right, its not a very happy future-proof phone in terms of spec. Motel75, that Lumia 630 looks quite interesting as does the Galaxy Grand 2 DuoS though a little more than I want to spend at this point.

Yes, indeed that brandy was worth a lot more than the phone that it poisoned. It was a gift (..the brandy that is). I had a connection via Manchester airport where normally you can happily stay air-side to transfer onto other domestic flights if you are travelling with only carry-on luggage... well of course unless you are flying Ryanair of-course!! So to cut a long story short, I had to go land-side, pass through security again, knowing that the bottle I had picked up at the previous airport would now have to be checked in. I unfortunately had no choice but to check in my carry-on luggage! And that was the end of my 5 year old Nokia E71...and a rather nice Brandy de Jerez Solera Gran Reserva.

Anyhow, back to its replacement I have decided to take my time and immerse myself into reading about the risky business of buying cheap Chinese handsets ordered directly from their country of origin. I am now also quite seriously looking at the iNew v3. Its sounding like one of the best mid-priced mid-spec phones out there despite only a 1850mAh battery which seems way too low! I can live without GLONASS support as my main handset does most things this would not. I am basically looking for a cheap secondary dual SIM handset for my Toggle SIM sitting with a local for the data access.

Thanks again for all the banter here! I will keep you guys posted whatever I buy and in the mean time if anyone has any further tips or tricks, keep sharing them!

I've had a Haier W718 for a few days.

This is pretty modest cost - mostly £65 on eBay UK (several sellers are abroad), or from about $90 direct from China. Looking now there aren't as many on eBay as a few weeks ago ...

It has 900 & 2100 MHz 3g, and IP67 dust and water protection. 500 MB & 4 GB memories. Android 4.2.2 on this one as supplied, i.e. with Google Play included etc (not on all of them)

I came to it after spotting the Lenovo S750 with IP67 but it doesn't have 900 MHz 3g, which it looks like European countries are shifting towards.

I haven't used it much yet, but it seems reasonable, with a proviso.

My home is a bit patchy for coverage on some networks. The 3g signal indication at 2100 MHz isn't as strong as say the Nokia 6120, more like the old 7600 was (all phones with Three SIMs), so it might lose 2100 signal a bit early in weaker areas. Maybe it's a cheap antenna issue like inquisitor mentioned above. The 2g signal indication looks better, so I'd guess 900 MHz 3g would be ok as well.

And maybe it won't be such an issue elsewhere compared to UK networks who do seem a bit mean on coverage. And of course most network SIMs have 2g and 3g, unlike a 3 UK SIM for which they've been reducing the 2g roaming.

I'm intending to do something like a local SIM for data abroad, with a UK one in the other. It's a bit of a luxury to some extent, as I could just take 2 Nokias, E51 and X6, and a 3g router, but Symbian has been dropped for most new applications nowadays, and I've never had the comprehensive version of Mobilevoip stable on the X6

I can heartily recommend the Cubot GT90 for around £60.00 on Amazon :)

It's dual SIM and dual core (1.2MHz). Camera is quite basic at 3.2 MP - but otherwise the handset is snappy performer.

Android 4 inch screen - very nice.

+Steve :)

I have a dual sim Moto G 8GB that I'm really happy with.

I also purchased a Lumia 521 and am not impressed with the sim tray. It wouldn't matter for people who do not swap sims, but the sim contact prongs are not as gentle on sims as the Moto G. The sim tray "template" itself is also a has more than a mm's worth of tolerance so it can be tough to position sim well and it is also annoying to shove out the sim. I have to use a paperclip or pusher as the sim tray shield only allows access to ~1/3 of the sim. Moto g's sim slot is spring loaded. I think the Lumia 52x is a great phone for the (sale) price. I'm just not convinced it is built for frequent sim swap, especially if your sim cards are hard to replace.

I think there are now dual SIM adapters for the Lumia series, although the ones I have seen are external and you cannot have both SIMs `live' at the same time - flipping between the two is as easy as switching to `flight mode' and back again though.

+Steve :)

A bit OT again, but I discovered a major drawback of a quad-SIM phone when I lost my iPro FX3 and had to replace four SIMs from three countries. Multiple SIMs are convenient, but you really are "putting all your eggs in one basket."

There's a French brand called Wiko which floods the market with dual SIM Android phones that are said to be of pretty good quality.

As an entry-level smartphone I like the Wiko Rainbow, which is currently sold for some € 150 at conrad.de (or from eBay.de).

CPU: Mediatek MT6582 Quadcore 1.3GHz
GPU: Mali 400
internal storage: 4GB
microSD slot: up to 32GB
RAM: 1GB
display: 5″, 1280x720px
networks: GSM 850/900/1800/1900, UMTS900/1900/2100
camera (front/back): 2MP / 8MP + LED flash
battery: 2000mAh (changeable)
dimensions: 146 x 74 x 9,3 mm
weight: 167g (inkl. Akku)
extras: dual SIM, USB OTG

No GLONASS or 5GHz wifi.

Rumour has it that Mediatek might release the source code of their chipset drivers into the public domain which would mean that Mediatek-powered phones such as Zopos and the Wiko Rainbow could receive an update to Android 4.4 (Kit Kat) in a few weeks to months.

However I just noticed some very interesting advantages of the Moto G dual SIM (XT1033) which perhaps justify the € 50 difference from the Wiko Rainbow:
+ GLONASS support
+ pentaband UMTS (850/900/1700/1900/2100 MHz)
+ Android 4.4 (Kit Kat)

Sorry to hear about the brandy drowning of your phone. Only a waterproof phone like a Sonim would have survived that scenario (there's also some dual sim waterproof phones out there).

Currently using a Blu D230 Rave dual sim handset as my primary phone. H2O(AT&T) in the 3g/gsm slot and Telna in the GSM slot. Works nicely but the screen is only 3 inches and it's a single core processor running an older version of Android. It's getting a bit dated and I need a larger screen, a better camera, more memory capability, and more 3g slots.

Upgrading shortly to a Feiteng H9503 triple sim handset that is being shipped by FedEx from Amazon. Should be in my hands early next week. Slot 1 is a microsim slot with 3g 850/2100 mhz and quad band gsm. Slot 2 is the same specs with a mini sim rather than the micro. Slot 3 is quad band gsm mini-sim only. Has Jellybean 4.2, a dual core processor, ability to take 32 gb micro sd cards, and a five inch screen.

Really wanted 3g in 2 slots so I can run:
1. My Telna(T-Mo USA plus cheap foreign roaming) sim chip in slot one (needs 3g WCDMA in some countries like Canada where no GSM roaming agreements). Decent foreign roaming rates and I like the postpaid billing with no long-term contract to my credit card (no worries about prepaid balances evaporating like some other roaming sim cards that went belly up in the past).
2. H2O/AT&T sim chip in slot two (better chances of completed calls in big US cities on 3G). Nickel a minute calls.
3.And a soon to be activated LycaMobile US/(T-Mobile and limited foreign roaming) sim chip in the third slot. Two cents a minute calls.

Data will be fed in most circumstances by wifi from one of 2 mifi devices (one is AT&T postpaid, and the other is FreedomPop/Sprint free service) or from wifi hotspots. Advantage of this setup is that both of the mifi devices are LTE so it will give a higher speed data connection than the new phone is capable of by itself. As a backup I will program in the APN for the Telna sim chip.

Saw your related [& vague---no details/specs]post on HoFo.
You are not planning to use Telna for 3G in the US, are you?
Looking forward for your reports and review.

Description of phone in the Amazon US listing: http://www.amazon.com/FEITENG-H9503-...keywords=h9503 Specifications are a bit fuzzy like many Shenzhen phones. From what I've heard the rear camera is really 5 megapixel interpolated up to 8 megapixels. Some dealers also claim it can take a max of 16 gb for a micro sd expansion card where others say 32 gb. Permanent memory is only 512 mb ram and 4 gb rom. The display is big but doesn't have the resolution of the name brands that it's copying. But it has unique features like triple sim capability and the price is very good.

Don't know if Telna works in 3g mode in the US. It's a moot point anyway:
-Neither the Blu dual sim phone I use currently nor the Feiteng phone in transit to me cover the T-Mo 3g frequencies (1700 AND 2100 Mhz or limited 1900 mhz refarmed spectrum as result of the failed merger with AT&T). 3G frequencies on both handsets are 850 or 2100 mhz.
-Also the Telna US T-Mo voice rates are 8 cents out and five cents in. Lyca is only two cents a minute.
What I really need Telna for is travel outside the US where they offer competitive rates. While T-Mo does offer cheap international roaming now...that's only for $50+/month plans. Telna offers a more practical solution for the occasional international traveler like myself. Certainly was cheaper in St. Maarten where I could place Telna calls on Digicel Antilles Francaises for a quarter a minute instead of the hotel room rate of $6 for the first minute and $4.50 for additional minutes.
Telna would make sense for me for US backup data purposes and international primary data purposes for the new phone because it's an easy to set up APN. I don't care if the connection is only Edge or GPRS in the US since my 2 mifi devices are both LTE with fallback to slower standards. It's no big deal to put a mifi device in a jacket pocket or in a small camera case on my belt.

Well, if Telna's agreement with T-Mobile is what Piranha uses
for T-Mobile in USA then it is a yes for 3G on T-Mobile.
The Piranha UK phone number I have says it is a Telna phone number.
[For what it is worth Piranha also uses AT&T and gets 3G on it also.]
I live in southern California so yes I am in a refarmed area.

T-Mobile near my home is only 2G and Edge and coverage is weak(nearest towers are shared AT&T and Verizon only). Near my office they have 3g and also patches of LTE. Using T-Mo for talk and text only so that's not important. LycaMobile will go in the 2g slot
AT&T is a strong 3G signal near my home and office so it wins one of the 3g slots in the new phone. And Telna will go in the micro sim 3g slot in the new phone because of some international roaming situations where I do have 3G or 3G is the only option available.
Thought of using Piranha but prefer Telna for inexpensive postpaid. Plus the Telna US rate is more reasonable.

Actually it's LTE plus 3G for AT&T near my home....which is why I have an AT&T mifi device and an H2O/AT&T sim chip.
T-Mobile is going to overlay about half of their US network with LTE by the end of 2014 and the remainder by the end of 2015.

I going to give this a bump and ask what people have come up with in the last year. There is a great Lumia dual SIM with great LTE coverage on both SIMs. I hear One Plus 2 will be dual SIM. What else is out there? Unfortunately, I think it is getting risky relying on pure GSM for voice as some carriers are starting to turn off GSM. I can get buy with HSPA, but would prefer LTE.