I use Fedora and KDE really sucks here. It is bearable only with minimal options and animations enabled. Only thing keeping me from ditching is that I'll have a long time picking something else that satisfies me, because I want a fancy desktop, but not a sluggish one. Have you seen a DE that features a couple of nice animations and effects and can mimic MacOS, but is lighter than KDE?
Xfce is just probably better optimized for X11 currently. Most of lightweight DEs probably are, I guess?