I tried WindowBlinds (can't remember which version, if any) on my K62/400 running Win2K (17" monitor @ 1280x1024 16M colours) and I didn't notice a drastic bogging down. But then, I don't do anything too intense like first-person-perspective shoot-em-ups and the like. It does make things look very XPish, but in the end I uninstalled it because I generally prefer a simple looking interface without all the "fluff". The least you could do is try it out first, there should be a demo or you could (rubs hand over mouth saying something about getting it somewhere on the net and trying before buying).
Pete
