I have had TMobile for a number of years. Mostly because I pay for four phones and they have the best rates. Until I knew better I had issues with their coverage. Turned out the problem was with the Samsung phones I'd used. Some phones simply get better reception than others. That can be as big a factor as "coverage areas". I did my due diligence and learned that with tmobile their blackberry and nokia phones get the best reception. Since I switched to Blackberry over a year ago I have noticed a big difference. I get a signal now in areas where I didn't, and I very rarely have a dropped call....and when I do it is often on the other end....not because of my phone. BTW.... I have a Blackberry Pearl 8820. The WIFI feature is pretty cool. My son uses his a lot.
My last phone was a completely touch screen phone with the virtual keyboard (samsung instinct) and after 8 months, I still couldn't type a word without making a mistake. I'm not saying vitual keyboards are crap, it's just that my fingers are probably too big for them. My next phone will probably be the HTC touch pro, because it's basically a diamond that has a keyboard.