I've been running it on a new quad-core Dell XPS420. I have a power-line ethernet network between the HR21-700 and the computer. Works great! No stuttering. Looks great on my 24 inch LCD too! Good Job DirecTv!
As a frequent critic of D* over HD DVR issues, I have to say that D* finally got it right with DIRECTV2PC. There have been times that it has just been way to convenient to sit at my computer (a quad core Pentium system attached to a 22" widescreen monitor) and watch what was recorded on any of the 4 HD DVR boxes in my home. Of course this gives me that opportunity to "see" what some of the "young ones" have been watching and recording. The only drawback (if you want to call it one) is that once any part of a program is viewed, the menu screen on that particular DVR shows that the program has been viewed, even partially. Heck, keeps 'em guessing.
Now if D* would only stop doing software upgrades during prime time hours. Well, we can only hope!