I am having problems with Comcast Internet service. It appears that they are not a reliable service as they are claiming to be. For some reason the service is not accessable for hours during the day. Regular cable service is available, but not internet service. Comcast tech support has told me the problem was with the modem and that I should get another one. Nope. Problem is with the service.
I can't recomend Comcast high speed Internet and if DSL is available in your area get it.
lukefisher.com details their experiences with Comcast and why they switched.