1. AT&T is about the slowest updating carrier. They also seem to be the one that has the fewest bugs in their updates. Maybe there's a connection there?
2. You don't base your choice of carrier on their phone availability, you choose the carrier, then choose among the phones that work on their network. The best phone in the world in a spot your carrier doesn't cover has very little to offer that a rock doesn't. Service counts too. I'd much rather hear, "I'm so sorry, I'm going to have to give you a replacement phone", than "We can't fix this here - it has to be sent out. That can take from 2 to 6 weeks."
(And personally, when CDMA goes digital it makes me queasy - if it has to be a digital signal [I grew up digging voice out of the noise on analog signals] I'd prefer the autotuning of GSM.)