If by "responsive, fast, reliable" you mean awful screen tearing when you mix X11, OpenGL, and/or video playback. Fixing it on any given machine is often possib

If by "responsive, fast, reliable" you mean awful screen tearing when you mix X11, OpenGL, and/or video playback. Fixing it on any given machine is often possible through some voodoo and a hand-rolled combination of driver and software settings, but that voodoo works only for one specific combination of hardware and driver version, and every update means more rounds of trial and error...