You can keep Compiz
If you want, and it is FOSS. I'm running KDE 3.5 on Debian Squeeze over here. Different strokes for different folks. Linux is just an OS kernel, and distributions are just collections of software packages. The rest is up to you!
I am beginning to think that the real trick is to do an "expert" custom minimum install with any distribution. Don't just pick "Typical Desktop", or whatever your distribution calls it. Then go from there. Either that or you will get stuck with whatever some pompous, swaggering, two-bit, tin-plated, dictator with delusions of godhood throws at you.
It works here.