I have had really good luck with Comcast at my old house. I just established service at my new house and nothing short of a nightmare.
The gas company cut the cable and Comcast insisted on a professional installation for $99 so someone could fix the cable. The guy came out and fixed the cable, but the tech refused to hook up my service because I don't have a TV yet. I had my cable modem there, but he didn't hook it up. I called and they switched it to self install, but they insisted I had to have my DVR hooked up before they could activate the cable modem. I spent 30 minutes in line at the Comcast office to get a DVR. I spent an hour on the phone getting the cable modem activated and it turned out I didn't even need the DVR to get Internet working.
My Internet quit and I called them. It turns out they switched me back to professional install and disconnected my modem even though it was up and running. After another 45 minutes on the phone I am back to self install and my modem is working again.
No wonder nobody likes these clowns.