ive been running comcast cable since april 1998...
though the speed is a serious complaint amongst myself and many of my friends who use it was well, as we have seen DRASTIC speed drops over the years (unlimited/400kbps -> 3.25mb/1mb -> 1.5mb/128kb), a compliment for comcast is he knowledge of their onsite techs as well as their schedule times, in comparison to other companies i have dealt with.
Up in NYC, it takes a week, at LEAST to get a tech out for time warner. Let alone the fact they are specialists. THe first guy only installed the modem...the second guy only knew how to do the same. I had to wait a week for those first two guys. I had to wait a week for the next guy to come out who only checked the line strength. THe final guy, who i had to wait another week for (all in all 3 total weeks of waiting) increased the signal strength and fixed the cable.
Comcast sends out one guy who can install modems, check the modems, check the signal strength, and fix the strength, all in one shot...and even do some cable tv things

. Wait time on these guys is AT MOST 5 days. On average its like 3 days. And the window of time to wait for these guys are ALOT smaller than time warners (cable companies are notorius for their LARGE window of time)...
And ever since comcast@home changed over to comcast.net, i have probably only experienced 1 or so losses of connection. With @home it was quite often i experienced loss of connection. Though with time warner, i havnt seen one in the 4 months ive had them.
THe phone techs are the same as any company. They are all idiots just reading standard textbook proceedures on how to fix your internet should it go out. THough they are smarter than time warner techs.
And at $40 a month, should you find a modem for free after rebate (either with or without proof of new signup...some circuit city deals or best buy deals will give you a free modem if you sign up to comcast thru them), the price is right...