Well you're in luck, I'm in South Florida.
One can't say they're terrible/amazing based on their sole experience. I've been with them for years and LOVE their stability and speeds. I typically download files at 3.0mb/second; I download a 1GB file in about 5 minutes. My connection is never down, and even at my old home in a different city had the same experience. Oh wait, at my old home it WAS down for a few days. It wasn't difficult at all to get a generous credit towards my next bill though.
AT&T on the other hand, at least down here, is horrible. EVERY single person I know that is on AT&T calls me every other week because they lose connectivity. Sadly I'm the family/friend 'PC dude' so it's gotten to the point where I hate AT&T and have told them all many times to switch to Comcast.
I give two thumbs up for you to go Comcast. I pay $30 a month for the most basic TV cable you can get with my internet.
Well, for the rest of my roomates who just web browse, ATT is fine. For me, it's terrible utter garbage. I've had some slight issues with my local ISP in the past after a heavy thunder storm w/ some down time. But it's really just to much $$$ for the speeds I'm getting.
There isn't much isps available besides att, local cable and comcast. I'd really like to know the upload speed though so I know if it's enough for my server