I haven’t tried Kubuntu 8.10. I do have an older Kubuntu box with no real problems, other than I think KDE installs too much stuff, and it hates my ATI graphics card.
What I've been seeing on other tech forums is that the latest KDE version includes a lot of extra 'conveniences' that've been added to the likes of Vista & Windows 7. The phrase 'fixing what ain't broke' keeps popping up a lot...