the kcontrol center by itself is quite good, the only thing that I can't stand is having a "settings" menu entry in the k-menu where all those apps "which would not fit anywhere else" are placed... this is very inconsistent, and confusing... I also think that keeping administrative tasks from user preferences would ge a good thing, just like gnome does... actually, that's the only decent thing gnome does
besides, i've just got back to kde after a looooong time and man am i loving it, kde 3.5 in debian sid is drop dead gorgeous!