Unfortunately, I don't. I have it loaded and I have used it by following strict instructions but that was a long time ago and I have long since forgotten what I did. I've been looking for concise instructions but haven't found them yet.
AFAIK when you run with KMS you get mostly tear-free 3D rendering which prevents insanely high frame rates. Shouldn't have much impact on real world apps, just things like glxgears which would otherwise generate frames 10-100x as quickly as the display can show them.
Yeah and if things work right and vsync is on, glxgears fps should equal your monitor refresh rate with a reasonable accuracy.