I think all the ads need more truth...
I am an ex comcastic sub... sure there signal at the head end might be outstanding (but no more outstanding then either D* or E* or any other provider) but by the time it goes a few amplifiers down the road not much of the signal integrity survives. Even in the digital world... all it takes is one poor connection. That is something most cable co's have plenty of (poor connections).
points i wonder about when reading such stuff:
1) I wonder how far from a cable head-end this survey was taken?
2) If both D* and E* were installed by professional installers?
3) If they swapped the signal sources around on the TV's with no adjustment to them to make sure they were not the cause of stated results.
4) If they were even using their compression when displaying there images Nothing says they are 100% of what you would get as a subscriber.