I've had Comcast TV and internet at my current house now for 8 years and am very happy with the quality and consistency of the signal. I felt confident enough in it that I dropped Qwest home phone service 2 or 3 years ago and bought an Ooma VOIP system. Once you buy the Ooma hub (for around $220), the phone service is free, including long distance, This saved us the $60 per month or whatever it was we were paying for voice service. Comcast's uptime is great. Not an issue.
Dealing with Comcast when you do have an issue requires extra patience sometimes. My wife hates them for their poor customer service. They just talked me in to the Xfinity "package" which offers remote viewing of some programs via the internet. It's not quite what I thought it would be. There is no viewing of live sporting events remotely over the internet.
My opinion is, once the "deals" are up, that you are going to pay any provider for the service you get. I hate changing for the sake of changing, but I am looking around. I would be inclined to keep Comcast internet because of the consistency of the service. I've also been reading a little about using a cable card and Windows Media Center, but I'm not sure it would save me any money.