Running them right now(6.67), there are a few glithces here and there, and Coolbits doesn't seem to work(no OCing that I have found yet).
The most notable glitch that I have seen so far is the shadows in Giants seem to be corrupted, but performance seems to be improved quite a bit(and it is very much needed in this game

).
Installing them is a bit odd, you first need to point the install to the "Disk1" folder, then skip the missing file, then point it back to the parent directory you extracted it to.
OpenGL performance seems a bit off at lower resolutions and higher resolutions, and gamma seems to have been bumped up quite a bit(first time I ever recall turning the brightness down, half way down, in Quake2 in game). No actual benchmarks here, all I'm worried about currently is how well Giants performs(everything else is plenty fast enough) and these drivers seem to be the best so far in that one area.