My first ever journal entry on /., hope it's interesting for you.
Moved from KDE3 to KDE4 recently. KDE4 looks interesting, but after all this time it STILL looks like a work in progress and not something that should be rolled out, still lots of bugs.
I've been busy deleting as much KDE3 stuff to leave just the bits that I still need for it to function with KDE3 applications that are not written for KDE4 yet. Other applications have KDE4 ports, so switched to those and removed the KDE3 versions.
The biggest disappointment is Amarok's move to KDE4. The new version is over complicated, looks awful, and is difficult to use. The new version decided all by itself that your music collection will now be powered by MySQL, so all your user collection and statistics are lost from KDE3 (I was using SLQLite), also all your galleries for the albums were 'lost', you'd have to add them to all over again (although all the images are in the KDE3 Amarok directories). Most the scripts for Amarok KDE3 were not in the KDE4 version.
After half hour of tearing my hair out over it, I un-installed the KDE4 version and re-enabled the Amarok KDE3 version. Sanity!
The desktop no longer functions as a desktop, so mine is completely clear of everything. The KDE4 team missing the point of a desktop. It may be restored as a proper desktop in future allegedly. Who knows.
KDE4 promises to be lower CPU usage, I've yet to see the evidence of that, but it may be because I'm still using bits of KDE3 to keep full functionality. The kicker bar replacement is a major irritation, it's 100% width and can't be altered.
Looks like features to customise the whole KDE look have been deleted, and is a major irritation. I don't want a standard Microsoft Windows type experience. This again will allegedly be fixed, who knows when.
Overall, KDE4 has not totally fallen over and is usable, but it's not as good as KDE3 is. So if you're thinking of updating to KDE4, don't bother, there's no hurry.