I have cable, and in all seriousness my company cannot even give me a straight answer on my theoretical maximums. They lied to me the first time over the phone (mentioned a 1.2 upload, for cable? yeah right!) and the second time around they gave me numbers that sounded more reasonable for cable (1.5 down/ 128K up) but I have not been able to get anywhere near those speeds, no matter the time of day or day of the week.
Doesn't matter that much anyways, as they are the only game in town. They have a broadband monopoly and I'm sure they've oversold whatever loop I'm on thrice-fold.
I have to power down, unplug my cable modem, and reboot every once in a while to keep it working. Better than nothing though.
I've gamed on other cable, ADSL, T3, and OC3 connections before. I would definitely get SDSL if it was available, it is the way to go. I won't be at this location any longer than a year, so I'm not too stressed.