'EWMH fullscreen hint instead of an redirect-override window [...] the way SDL does it is that it ignores the window manager'
Of course, this is all useless if the game doesn't support it and you're locked in for the entire session... hence why I've been playin s2 only recently. This basic feature is kind of very useful.
I don't know why but SDL never made me fly. It's a good idea but somehow the execution is a bit... lacking :/
I think SDL 2 (AKA 1.3) is supposed to be a much better, cleaner implementation, with a LOT of additions.