my previous response never got posted... do here goes again:
I have been with Fido since 1998: they started out with excellent 1900 coverage in urban areas but with limited rural coverage, and they were bought out by Rogers a couple of years ago. Rogers implemented mostly 850 coverage extending to rural areas.
Both networks have now pretty much been merged, but it would be fair to assume that 1900 coverage in urban areas is still good with Fido. An excellent source of information can be found at
www.howardforums.com in the Fido or Rogers forums.
Good luck...