I re-installed Red Hat 7.2 at home and installed KDE 3. You need to update RPM, popt and a few other things first and I didn’t install the usb/gphoto/kamera rpms because of file conflicts with Xconfigurator.
KDE 3 is nice. I only played with it for a few minutes though. The biggest difference I’ve seen so far is that kmail uses Maildir by default so I have to figure out how to import my mailbox format mail into it. I’m sure that’s a FAQ somewhere. I’ll probably move to Kmail from Netscape Mail in work too as it has some very nice features.