Pros: They've done the job for me, Rollover
Cons: Expensive Data Plan
I pay $90/mo
-450mins rollover (fortunately for me, i'm a big text/email guy)
I think some other carriers are cheaper, but don't have rollover (which comes in handy during the talkative months)
Support has never been stellar, never been crap. They're just in the middle somewhere
It really depends on where you live/frequent. I live in Cambridge, MA. I get good reception out and about, but it's OK where I live. I get 1-3 bars. I've solved this issue by using a bluetooth headset and placing the phone in a good location
I've always thought AT&T has had great phone selection. I'm sure apple afficionados would concur. In any case, given the GSM nature of the network, you can buy any gsm phone and get it unlocked. This means that you could get crazy pimped out phones online.
I've been happy with them. I'd be ecstatic with them if I were paying 70/mo and the service were a tad better.