I've had Comcast twice and Verizon twice.
I can say with first-hand experience that Comcast customer support is far superior. On average with Verizon, I would be on hold for about 15 minutes before I was transferred to someone else. They could not help me, so I would get transferred again, and would once again be placed on hold for another 15 minutes. On several occasions, my girlfriend and I both were on hold for over 2 hours for various issues (billing, service interruptions, etc).
I've never waited more than 5 minutes to speak to an actual person at Comcast. If I ever need a house-call from a tech, it happens within a week. With Verizon, I waited 3 weeks to have them come out and fix a problem they caused when they installed FIOS the first time.
Now here's the trade-off. I was much happier with the FIOS service itself once it was working properly. The FIOS on-demand is superior to Comcast, and the UI is much better and faster as well.
Sorry for the derail!