I use Rogers Canada. They finally have excellent Ontario coverage nowadays since November 2003 when they deployed the new GSM850. Things like the Toronto Union station jumped from just 1 bar to 5 bar, and two-level-down-underground parking garages jumped from 0 bars to 2 bars. I can get 4 or 5 bars on my 7280 in places where old Rogers phones only get 1 bar! On top of the excellent RF electronics in the 7280, it is reported by HoFo members with signal testing, Usually the improvement is only 2-3db but some places actually show a whopping 10db improvement. And that is from the same celltowers in the same location! A good thread is
850/900/1800/1900 Breakdown & Info thread on HoFo.
I heard Bell has excellent coverage. As it has been a while since I last used Bell Mobility, I don't know how they compare. But I think they compare well in Ontario, I sometimes get better reception than some Bell users with the excellent 7280. But it is phone-dependant as well. (not in certain places like PEI -- Bell is better there, no doubt!!) But Bell is a bit slow with Blackberries, and the CPU in the CDMA Blackberry 7750 is super slow compared to the 7280, meaning applications take much longer to load on the 7750 than 7280. Hope this is fixed in a future Bell CDMA model.