Got this last week. Nice device, but I had to try three different Comcast cable cards before one of them worked. An install tech told me it almost always takes one out of three to work. After this, it took three separate phone calls over a couple of days to get my premium channels like HBO working. In my opinion, Comcast is maybe purposely sabotaging the install process, in the hopes that people give up and stick with their $17 per month DVR. When you go pick up a cable card, get two in hopes one will work. If neither of these work, go back and swap two more.
What I really like is how all my Windows computers on my network have access to these three tuners. I also like that because I have some large hard drives, I can record over 100 hours of HD, and potentially way more, while my DVR was limited to maybe 20 hours of HD. The picture quality is good. The tuner changes channels very fast. I like how if one tuner is recording, it automatically gives you access to one of the other three tuners. My Comcast DVR only had two tuners.
$130 cost of Prime HD divided by $17 DVR monthly rental cost means it would take eight months for this to pay for itself.