Well, I love KDE. I find it to be a much more well thought out Desktop Environment. I would use it except for issues with Compiz integration, and just a general lack of Ubuntu support. Plus, it's rather difficult to make KDE3.5 look good. I love the KDEMod theme, but I can't find a version of it that works with Ubuntu.

Anyway, I'm babbling. KDE4 looks beautiful, and leaps and bounds better than KDE3 (imo). I've tried it a couple of times, but it doesn't have a lot of the features I would need to make it my permanent desktop environment. The composting manager is way too slow, most of the widgets/plasmoids are a bit useless, and I can't (well) resize the dock/panel thing. 4.1 also looks great and seems to resolve a lot of those issues. My questions (for now) are these:

How stable is KDE4.1? Are most of the problems with stability (crashes), or just lack of polish (buttons not existing, or being in silly places... that sort of thing)?

What do you do for compositing? From what I've seen KDE4 compositing just isn't ready yet. How well does KDE4 integrate with Compiz Fusion?

Do you find yourself having to use Gnome apps often?

Do you find yourself having to use KDE3 apps often?

What are your favorite KDE4 features?

What bugs you the most?

I posted this here because it's not a support issue. Please move it if there's a better place for it. I also really don't want this to turn into a Gnome vs. KDE thread. I'm just looking for some information. I'm sure at least a few people are wondering the same things.

Please feel free to answer whatever questions you think you have good input for. Also: feel free to add questions to the list so this thread can be helpful to more people. Thanks!