It is growing on me. I have been using it off and on since January and have seen
real improvements. It is faster than KDE 3.5, but it isn't as configurable, ...
yet. When it first came out it wasn't configurable at all and it was big and
clunky. Now it is on par with Gnome in terms of configurability. If this is
acceptable then KDE is worth a look.

To like KDE 4 you have to change your thinking a bit. It is a totally different
experience from KDE 3.5 or Gnome. Don't expect it to be like either and try to
embrace what they are trying to do and you will like it, too. If you are wedded
to the Gnome way of doing things or KDE 3.5 then you will be disappointed.

I still don't like the slab menu which is small and requires too many mouse
clicks IMO. I like the desktop widgets and wish there were more of them. I like
the themes and decorations. I want more, of course. Choice is what I crave which
is why I like Linux in the first place. Not having it drives me around the bend
and patience is never my strong suit.

KDE 4 uses Oxygen which is a separate project and this tries to incorporate a
more modern crystal or realistic effect, ie. not as cartoonish. Plasma the
widget and desktop decoration engine is an improvement and an attempt to give a
look and feel on par with the Mac or Vista, similar to what you might get with
Google Gadgets or Screenlets. KDM 4 also has built in compositing, so there is
no need for Compiz Fusion, but then again you lose all of its cool features. I
have used Compiz with it, but I have not found out how to turn off built in
compositing yet. Truthfully, I have not seriously tried.

I think that I know why Ubuntu switched to KDE 4 with Kubuntu 8.10. There will
come a time when 3.5 won't be available at all. Right now KDE 4 is stable and
has enough to satisfy most people in terms of features, configuration and
applications. They always like to be ahead of the curve, pushing the envelope.

Most applications have been rewritten since KDE 4 uses a different programing
environment. If you want to install some KDE 4 and KDE 3.5 apps you will need
separate core libraries becauseit is based on a new version of QT (4). This move
in itself is exciting as it will allow it to appear on Windows and Mac machines
instead of their own desktop managers, giving dual and triple booters the same
look and feel in all OSes. This also gives KDE its performance improvement.

While you can jazz up KDE 3.5 so that it looks as good as KDE 4, this all comes
at the cost of a performance hit which does not happen with KDE 4 due to the way
it is built with improved memory management and processor speed. KDE 3.5 is on
its last legs. It has served us well, but it is time to move on which is why I
moved to the new Kubuntu over the old.

Note: I have messed up KDE 4 desktop several times by simply trying to configure
the desktop effects. When doing so I lose everything and just get a white
screen. This has happened to me twice. The way to restore it is to delete the
.kde folder in your home user folder which is not easy to do unless you have
another desktop installed. Fortunately I do. I just Ctrl+Alt+backspace and then
log into Gnome and delete the offending folder which when I get back into KDE 4
starts me fresh. You could do this from the Live CD if you don't have more than
one desktop installed.

I don't know why people don't have a second desktop installed. I have saved
Gnome or innumerable times from not working by booting into XFCE or the other
desktop from the one not working. Of course it is the tinkerer in me that gets
me into such trouble. I can never leave well enough alone.