Designer Mike Davidson is having major Tivo withdrawals after moving from a DirecTiVo combo unit to a Comcast HD DVR. Mike offers up a comparison, but the most telling quote is this one:
I’ve begun watching less TV simply because I hate interacting with it so much.
I know others that call the Comcast HD DVR "the worst interface on earth." Like I said a couple days ago, I hope CableCARD support becomes widespread so that customers that want HDTV without an ugly dish can still use Comcast, but not be tied to a set-top box they don't like to use.