Wierd. I have Comcast and I play Demigod fine while streaming music on Pandora. Normally I only encounter lag if there is a high-ping player in the game. I hosted with listchecker on Warcraft III on this connection without too much problem either. I live in the southwest VA area. If you live somewhere else I'd say it's your local cable node being saturated with users. Try to avoid playing during peak Internet usage hours (5-9pm I'd say). Conversely, I have noticed that if you play late at night when Internet usage is low, you will experience better performance. I always stay up late to play and after 12am pings are noticeably better.

Depend what area you are in with comcast, you would be in hell or not.

In areas where comcast don't have competition, they can give rat ass about you as you have no choice anyway.

In area where verizon had invaded with FiOz, comcast is still trying to put a good service so they dont bleed customers. Or, rather... they are allocation all their resources and time in area verizon had invaded.

Just basing on my observation after my local area's cable company got bought by comcast and I am now forced to use comcast.

Of course, I could be wrong. But the shitty performance is what I have to suffer with every day, which didn't exist before comcast force its way in.

Another way to put this...

If your area only have comcast, that means EVERYONE is on comcast, which comcast can't handle well at all. That means very limited bandwidth during day time, when people are awake.

Some information.

http://gigaom.com/2007/05/11/5-truths-about-comcasts-super-modem/