Reading that keeping X in 3D mode tends to use more power convinced me to finally drop compiz.
Back to metacity, I found it unusable. I've always used Super+Right mouse drag to resize windows, and metacity refuses to do that. I haven't found a way to resize windows with it other than dragging the super-thin, impossible-to-catch window corners or using the keyboard.
I had a look at
debtags search x11::window-manager (I found
debtags tagsearch window) and picked
Quite light, standardards-compliant, it seems to handle everything as it should (gnome panel, popups, fullscreen applications, name it).
It has a very simple configuration dialog, just like metacity.
Unlike metacity, it also has a configuration file in which I can tweak those things that are not in the configuration dialog. And it supports much more of those than metacity does.
So, here are three use cases that weren't covered by metacity (or compiz, in case of RaiseLower) and are now fully covered by openbox:
I now have resize on right-mouse-drag: useful because applications don't often start with the size I'd like them to.
I now have RaiseLower on Super+Esc, to quickly see what's in that partly covered window and then but it back where it was.
I can now move windows beyond the top edge of the screen, to reveal those "Ok" buttons of stupid dialogs that for some reason are taller than my screen.
And also, the fan of my laptop is not on all the time anymore.
many people wrote me to say that it's possible to resize a window in metacity using Alt and middle mouse button drag; it is however impossible to configure it to use Alt and right mouse button drag, which would be nice to have on a touchpad.
I've also been pointed out that it is possible to move a window beyond the top edge of the screen with metacity. It is not possible to do it with compiz, though.