The October 18th release date for Ubuntu “Gutsy” approaches fast. It currently defaults to using desktop effects (the Compiz window manager instead of Metacity). But compiz is still appalling. In particular, it behaves terribly together with the GNOME Panel, with windows appearing under the panels or over the panels, and sometimes drawing its shadows over the panels while otherwise being in the correct position. In the past I experienced various focus problems, leading, for instance, to unclickable foreground windows. I don’t know whether those focus problems have been fixed – it’s hard to have the patience to test it completely.
Window managers are meant to be irrelevant to users, just doing obvious things so you don’t have to think about them. But Compiz generally makes Ubuntu feel so utterly broken that some average non-technical users may suspect intermittent hardware failure or a malicious virus. I wonder if this is likely to improve before the release.