Okay, I did it. Most of Saturday and most of Sunday was spent using KDE4. Overall it was a good experience. I only had two applications crash, but I’m not sure which ones they were (strange, but true). If it wasn’t for the video screwing up in VLC and Mplayer I would have used it all day Sunday. I forgot to try disabling the compositing, though. I wish I had remembered to do that.
I think I’m ready to switch over full time, once I get that figured out.