We had Comcast, and last year over multiple different problems experienced the worst customer service ever from their office people to the techs who never showed up for their appointments that i took vacation days for, to the idiots on the phone... Switched to Uverse as soon as it was available. the few customer service issues we had, their phone people were top notch, and their techs who installed and fixed our problems were great.
Also - for the same amt I was paying monthly at Comcast for cable and internet, we get noticeably faster internet and more channels, esp more HD channels. They seem to add 4-5 HD channels a month lately too.
Also, Whole house DVR is really nice. HD quality wasnt as good as comcast a year ago, but watching HD from Comcast at a friend's recently, I'd say now it's about the same.