I promised to post my experiences with KDE 4.0.2. Here we go.
All in all, it seems far more stable than the previous 4.0 releases. Especially konqueror hasn't crashed on me since I switched. That's really good. Maybe, I can switch to new windows (in konqueror) again instead of starting a new process for each window.
The panel is now configurable - to an extent. One can configure the size and the position (button, top, left, right). The vertical positions aren't very usable yet; things don't match. It's still far away from the panel in 3.5. One can't drag icons around and such. It's still an ugly black thing that cannot be changed.
Animations (menus and such) seem far faster, but this can be due to my installing a new (xorg) driver for my video card.
There isn't an easy way yet to launch kmail from KDE 3.5. I have to open a konsole, type "/usr/kde/3.5/bin/kmail" and close the konsole after kmail appears. Nothing you can ask customers to do.
No fault of KDE at all: I can't get composite to work. Although I found an OSS driver for my video card (
http://www.openchrome.org for my VIA UniChrome Pro chipset), I cannot use any of the effects using composite in KDE. The moment I do, my whole session crashes. Let me emphasise this: This is a fault of the chipset/driver. Has nothing to do with KDE. Still, it deprives me of all those nifty effects in KDE.
That's it so far. Facit: While I will continue to use it, I cannot recommend it to my customers. We still have to wait for KDE 4.1!
Uwe
