U-V (I hate this name) is AT&T's high-speed service; it's FTTN (fat pipe to a DSLAM in the alley) 10-15mb over phone copper. It's a triple-play service (you get your TV and phone over it). I know a bit about it because, uh, I have it.
Dillon is pissed because the U-V router/firewall, which you can't really replace, is so bad that it breaks power user configurations. He's right, it does. BitTorrent also chokes it (yay!). I can add other problems: the set-top boxes are flaky, the reliability isn't awesome, customer service is atrocious.
On the other hand: it is f-a-s-t and cheap. I had Comcast before it, and before that I had Speakeasy (who I'd been loyal to since before the Best Buy takeover until I couldn't ignore the terrible performance anymore). I wouldn't go back to any of them. I hear good things about Vzn's fiber service, but in Chicago, I think AT&T is the best available bet.