I just have to say I had a great experience with a Comcast installer. I wasn't going to be home when they were dropping off the HD box, but my wife was. So I just asked her to have them drop it off so I could set it up myself. Partly because of the rat's nest of wires tucked into the TV armoire the aforementioned wife limited me to.
Not only did the guy from Comcast set the box up correctly, connecting it correctly to the receiver and TV using the cables I had set out for it for when I got home, deciphering my rat's nest of wires, but also left a note saying since I had a 1080p set that he changed the output to 1080i, and flagging the page in the manual if I wanted to change it to 720p.
Needless to say I was more than impressed. I may be in the minority, but I did get some top notch service from them.