Edit: Unfortunately, the images originally included in this post are gone, because of hosting problems in late 2009. My apologies.
Just to be snotty, I installed xcompmgr on this laptop, knowing full well that it wouldn’t work because the video card can’t handle transparencies, and it has almost no video memory, and it was never intended for eye candy of that caliber, and blah blah blah.
I was wrong.
Desktop responsiveness is about the same, believe it or not. Some of the menu fade-ins are a little sketchy, and moving a transparent window around the desktop stutters a bit, but other than that, it works fine.