Yes, I am one of those grumpy KDE 3.x fans who can't deal with KDE4. So I've been trying out different desktop environments and window managers to replace my beloved KDE, and it has been fun and enlightening. In the past few weeks I've tested XFCE, LXDE, Fluxbox, FVWM, Ratpoison, IceWM, Afterstep, and others I have forgotten about already.
XFCE, LXDE, Fluxbox, and IceWM are my top four, and I seem to have settled on XFCE on my main Debian Sid box. It's similar to a stripped-down KDE 3.x with the feature set that I like the most. It's peppy on an AMD Sempron 3000 with a gigabyte of RAM, and really, any operating system that isn't peppy on this system is just plain obese. The most excellent cool thing about Linux is it's easy to try all these out, and underneath it's the same Linux and everything works. All Linux applications should work in any graphical environment, even though some folks act like using non-Gnome applications in Gnome, or non-KDE applications in KDE introduces unacceptable impurities. Whatever, to me it's all Linux and I mix-and-match.
Those happy mix-and-match days may be coming to an end, because installing any KDE4 applications also installs kdebase and a batch of libraries.