Hi :) I just looked at the khelpcenter page for the desktop effects and realized there is not much help for the question I was looking for:
It really would be helpful if you could describe which settings lead to a better and which to a faster desktop. At the moment (KDE 4.3 RC3) this is only available for the texture filter setting - but how about Composit-Type, OpenGL-Mode, direct rendering and VSync? And what's this about better window management? What does it do? And does it make the computer slower? Keep up the good work. Best Susan