The wife's laptop runs WIN-7 so that does OK with the native Media Center app. WIN-7 Media center is artificially limited to 4 tuners... MS knows best... at least they think they do.
I've not seen a need to use Tuner salad to bump that up to 8.
I'm still running my DVR function on my XP box. Using the native scheduler utility + my custom batch files and VLC. There is no limit to how many tuners can be managed this way.
Presently, I'm working on a HTPC based on Mythbuntu. While I have it working, there are several hardware issues due to a lack of open source support for the video adapter currently installed.