Compiz 9.5 still works with KDE 4.6, however with some limitations.
- OpenGL keeps stable even by installed VMPlayer with no known issues.
- Kickoff and bars work batter, I Still recommend to use just a couple of little hidden bars containing necessary applets like the tray or device notifier, using instead cairo-dock as main bar (a lot of work to configure it). The cairo-dock tray will cache what the system try didn't cache.
- The personal settings applet will accept the compiz selection first after a few tries.
Known issues:
- The only working window decorations are:
1) metacity or gtk2 decorations.
2) smaragd decorations, the ones with square corners are perfect. You will find thousand of them by dedicated portals for:
-- emerald decorators
-- kde decorators
-- gtk decorators
as *.emerald files.
The KDE 4.6 windows decorations can't work by reason of the still undefined metric, i think.
- Compiz can crash and disappear by leak of memory. In this case just type "compiz-manager" instead "compiz-manager --replace", because there is nothing to replace.

Finally, I feel the difference between Compiz and the KDE desktop effects like the difference between american and german movies, just matter of taste.
...but under KDE the windows also wave and shake a little bit...