I have a local cable co., Thames Valley Communications. They have a 30GB/month, 2GB/day max download. I know I've gone way over the daily cap a few times, not sure about the monthly. When we had Comcast, I definitely would have maxed it out. I suspect TVC is doing some kind of packet filtering/QoS, as torrents of dubious origin hit maybe 70KBPS on a good day, but legit ones from, say, OpenOffice can almost hit 1MBPS. With Comcast, everything ran really, really fast. I would usually pull torrents down around 300KBPS, sometimes more.
I'm seriously considering switching at least my TV to DirecTV, though. TVC has about 10 HD channels, which sucks. DirecTV would mean about a $20/month increase in price, but at least I'd have more HD channels. My parents have them, and have never had a complaint.
As to internet, dunno. I haven't caught any crap about overages yet. They're a local company, and usually pretty nice about giving out freebies. I got my install done free, and free HDMI cables. Comcast's customer service blows, but at least they have decent speeds, and a relatively high bandwidth cap.