KDE is not the OS! it is simply the desktop! If you are not happy with it there are many others to choose from that might suit your needs better.
Quite right. I should have said "interface". As for other managers, I've tried Gnome, LXDE, and Enlightenment. Didn't like any of them as much as KD3.
If I could run 3.5.10 on top of the newest kernel I'd be very happy. But that issue has been discussed here ad nauseum.