Sushi,
Do a specific search on the Revo. There were a number of threads on it when it was released. I believe quite a few people were planning on using the analog outs for DVD-A and such with experiences posted on the stereo analog out capabilities (as the software wasn't present when last I looked at those threads). There should be SOME info for you though I've never seen anything that documents the testing procedure behind the claims of M-Audio.
Personally, I plan on using the Asus A7N8X deluxe. It actually has a Dolby Digital encoder built into the south bridge. Everything is encoded into DD and passed up the SPDIF should you turn on that feature. The net result is positional sound in games which isn't exactly possible under any other solution. Every other card's digital out is merely a pass through in games not encoded in DD (Doom 3 being one of the few if only once it's released) resulting in stereo sound. You can use DPLII to then get some form of positional audio out of it, but that's not really the same...
I don't intend on using my HTPC for gaming often, but having it hooked up to a big screen and my Axioms, it will certainly be used as such some times.
