Don't you also need to have a good software player that supports DTS?
Why can't nVidia get NVDVD back out already? I hate all the players I've used so far, and WMP has to have the codec or something from one in order for it to work (well, at least mine says it does now, although it used to play them fine without). WinDVD requires special audio packs that cost like $30 to be able to play DTS and other formats.