I just installed the kx drivers.
After a few initial problems, they are absolutely great. All my games work with them, audio is noticably 'cleaner' and that's about it really.
Of course your milage will vary, friends have tried these and got BSODs, but for me they are amazing. The only missing thing (for now) is AC3 support, but my media player can mix the AC3 to stereo so it's not too big an issue at the moment.