Also, it still doesn't let me alt-tab into programs on other desktops
Found it; it's actually in the same place as in KDE 3, so I can't blame KDE 4 for my inability to find it.
It's in System Settings -> Window Behavior; there's a checkbox that says "Traverse windows on all desktops".
So maybe I'll screw around with the thing a little more. I'll probably have to make the switch sooner or later -- 4.2's due out in January; maybe that'll be the magic number. In the meantime, I am officially behind the times on Kubuntu releases.
EDIT: Yeah, actually it's working more or less satisfactorily now. Still can't upgrade to Intrepid because I'm using the KDE 3 Kicker/tray/whatever you call it. (EDIT 2: Panel.)
Some of the OpenGL effects are obnoxious, while some, like transparency and drop shadows, are pretty much essential from a basic usability standpoint, and reveals that KDE 4's UI design isn't nearly as stupid as it seems without OpenGL. Others fall somewhere in-between; the Alt-Tab effects are neat in theory but don't play well with transparency (picture a bunch of transparent windows all stacked one on top of the other -- like exposing the same film more than once). The Expose-style shit is keen, but I think you can get that set up in KDE 3, too.
From what I understand, the fancy OpenGL shit also doesn't turn off when you're using a fullscreen program, which is stupid; obviously I won't be using KDE 4 for gaming.
EDIT 2: Akregator 4 still crashing. I suspect it's because I copied over my settings from 3; it might work better if I nuked them and started from scratch. But I'm not sure I'm ready to expend that kind of effort.
I also can't seem to get my volume keys to work; I think it's something to do with KMix 4 not wanting to play with the KDE 3 panel, but I'm not 100%. But that's not a deal breaker; I think I've got all the deal-breaker shit resolved at this point.
EDIT 3: MPlayer, when using the OpenGL output, has some serious picture problems; frequent white flashes. Assume this is a conflict with all the other OpenGL shit KDE 4 does (see EDIT 1, "which is stupid"). The other graphical outputs don't want to play nice with my video card, so I'm going to have to find a workaround...
...later, because it's 1 in the morning.
(And no, I don't really expect most people care about my exhaustive list of things wrong with KDE 4. But these make for excellent notes for the NEXT time I come back and see if all my gripes are fixed!)
EDIT 4: Okay, yeah, the video flicker is due to a well-documented conflict between the ATI proprietary driver and Compiz. I figured as much. Will see if there's a fix; otherwise I guess I can remove Compiz and lose all those OpenGL desktop effects, which are less important than a functioning movie player.
EDIT 5: ktorrent 4 has been eating cycles and memory like candy. This may have nothing to do with KDE4 as a whole, as I've been using ktorrent 4 even under KDE3 for the past several months (ktorrent 3 has a nasty tendency to flood the router with bad packets until it brings our entire network down) and it behaves similarly there sometimes. I'll need to play with it longer to figure out whether this was a fluke.
EDIT 6: figured out the volume problem; turns out I needed to set it up in KDE 4's system settings even though I'm using KDE 3's version of kmix. So that just leaves the video flicker. Which may not have a fix except for turning compiz off.