You fooled me once (KDE 4.0). And shame on me, you fooled me twice (KDE 4.1). Don't expect me to try KDE 4.2.
I too wasted inordinate amounts of time on KDE 4.x. Our laptops and desktops now run Debian Lenny which comes with KDE 3.5.10 - undoubtedly the best KDE release to date and supported by Debian for some years hence.
Kudos for all the experimental work that the KDE team is doing in 4.x. If they keep the good and throw out the bad then there is reason to hope that the KDE 4.x series will eventually surpass KDE 3.5.10.
But as a useful working environment, rather than as an interesting programming exercise, KDE 4.x still has a lot of catching up to do.