Well I am in colorado and becasue of the mess to get OTA denver stations and my desire to get both high speed internet and ABC HD for the super bowl (damn broncos) I added comcast last month.
I have been with D* with them from the beginning (okay two months after the started business). I came from C band type of setup before that.
The quality difference on Discover HD is noticable being that cable is better though not by a bunch. Recordings of CSI which I get the feed via CBS west on D* are very similar. HBO hands down is much worst on the D* than Comcast and ESPN did vary between being as good on cable to being worst mostly was program dependent.
The receiver I have for the cable is the Motorola 6412 model and I am comparing with the Hughes HD-Tivo for Direct TV. I have checked with both a Mits 52 inch DLP rear projection screen and an infocus 7205 front project which displays at 10 feet horizontal size.
Additional notes are I have watched the history channel, hgtv and Altitude SD channels and D* is better than cable.
It has been over 15 years since I have had cable anywhere near my system but when they ran fiber within 2000 feet of our sub-division I guess the performance can occur.
I like watching hockey a lot and since I do have center ice still with D* I will continue with both for the next few months and report back any additional information. The challenge of course is there is no metric that I could provide that would allow others other than in our area any real data since each cable system is different. Though I will say the Motorola box kind of sucks in performance and capacity compared to the Hughes box except for guide menu speed
Bottom line is I haven't decided yet but I am leaning toward cable for at least the next year even though I have thousands invested in D*.
I haven't seen slacker post in a while here but he has a similar setup with both running at the same time.