I can't get used to Gnome, can't get used to KDE4 (and while we're at it - also not to Windows 7). Maybe because I grew up with older Desktop Environments, but nothing even comes close to KDE 3.5.10 for me. Since I updated to Debian Squeeze which no longer used KDE 3.5 I've stopped being happy when working on my system :-( I'll have to check-out Trinity at some time, I'm just a little worried if that project has the man-power to really keep KDE 3.5 alive.
When was the last time you tried KDE4? I found that it was very unstable and buggy when I first tried it when it came out. Nowadays it seems stable (haven't had it crash anymore), and much less buggy (ie. normal level of bugginess).
> I found that it was very unstable and buggy when I first tried it when it came out.
My problem with it isn't bugginess, it's that they'd removed the existing UI and replaced it with new stuff that worked differently. This means that I no longer know where to find stuff (e.g. for configuration).
Also some of the new interface I really don't like, e.g. they have replace the main menu with a scrolling menu that only shows a few options at a time, so I have to scroll up and down to see all the options. This "feature" on its own is one I dislike so much that I will not willingly use this interface.