I think that's very much personal preference. I tried KDE a few months ago and I couldn't stick with it; it is slower than Gnome in a lot of ways, it's (to my eyes) much more cluttered, and has lags at annoying places. For example, I tend to hit the windows key and start typing to launch things, but under KDE there's enough lag before the menu opens that it doesn't catch my first few keypresses.