NYC/Brooklyn with Cingular and SE T616.
Once it hits 9pm, the network is ridiculously busy. I've had to attempt to call more than 10 times before it actually connected, which is extremely frustrating if the call is important. People who call you may end up straight to your voicemail. It seems to be getting slightly better (I only have to call 5 times before it works
), but I really do plan to drop the service once my contract is up. Rollover is useless unless you have a sporadic calling pattern, because you'll either end up with a ton of rollover because you never reach the max (in which case you probably won't ever use the rollover before it expires) or you'll end up with zero rollover because you always use up the max.
With that said, I've never had a problem with dropped calls and the signal strengh is much better than my sister AT&T V60/TDMA (not saying much...) and my friend's AT&T SE??/GSM.
Bluetooth is nice for tranferring things to my comp, but the novelty wears off after the first month. I hardly use the camera on the T616 because it's fairly crappy. Also, unless you're paying for the extra data services, you can't use your phone as a modem either. Cingular doesn't offer free csd calls (which, I believe, they used to do). The T616 is unlocked though, so I can potentially use the phone with other services (but note that it's 850/1800/1900, not 900/1800/1900 like T-Mobile and the rest of the world).
Try howardforums.com for more feedback.