KDE 4.2 is really good!
I didn’t like 4.0 and 4.1, too many bugs and low level of usability, but the 4.2 rocks.
I installed the 4.2 on Kubuntu 8.10 without problems.
You can explore KDE 4.2 also watching some nice Video Guide.
Thanks to the KDE communty for this very good product.