As I mentioned in another thread, I just got an HD Home Run and an Eye TV hybrid and have it working on a Core 2 Duo Mini. The whole thing works rather seamlessly and the only thing which will be visible to anyone in rhe room when I'm done is the mini itself. Um, right, and the TV. Right now I have the HDHR hooked up through a leftover hub but I got a gigabit Airport Extreme the other day and when I have some time I'll hook it up to that.
The looks on the HD Home Run are below average for most Mac users and completely normal for most PC users. But it's a network device, so there's absolutely no need to complain about the way it looks. Put it up in the attic if you want.
I control everything through my Harmony remote, where I've set up an activity which includes IR commands from both the Apple Remote as well as the Eye TV remote, and I also use Sofa Control for controlling pretty much everything else (iTunes, iPhoto, Front Row, etc.) Still waiting for the new BT keyboard to arrive, but frankly I suspect I won't be using it much (I did a majority of the setup through Remote Desktop).
It's clear that EyeTV is still testing the waters when it comes to their software controlling multiple devices. Every once in a while it gets "stuck"--doesn't freeze--but prevents you from switching tuners. Easy enough to quit and restart EyeTV, and I'm sure they're working on it and other deficiencies in the user experience of EyeTV.
Anyway, feel free to ask away if any of you have questions. I'm surprised I got this all up and running so quickly; I was giving myself 5 days to get everything working (I'm a 22 year mac user and an electronic musician, but I know squat about HD) and it took less than two hours. Unpacking the stuff took longer than getting it working.