The internet is fast and in my opinion a pretty good value. In my area I have rarely seen slow speeds or outages. In the case of outages it has only for a few minutes and usually happens when its real cold outside (say -20).
The TV service I feel is a bit overpriced however this is also the fault of the providers. Too many channels have infomercials late at night and I think Comcast should use that point in their bargaining with the networks.
As for tech support, it's really a "Your mileage may vary" type of situation. Simply hang up and call back in 10 minutes if you get a bad rep. You will get a different rep on the next call. Works every time
I currently have Digital Classic with HD (and a DTA box for another TV) and Internet.