I think that in any MPlayer FPS game vsync should be turned off. My LCD monitor can only support up to 75Hz. This means If I switch vsync on, I won't get more FPS than 75. It won't have tearing effect any more, but can you imagine playing quake on 75FPS? Besides as Lorfa has already mentioned, on top of that, vsync introduces some kind of input lag. I literally can feel that crosshair does not follow mouse as soon as it has to. I think even if I had 140Hz CRT monitor it would be the same.
So I'd just turn off and forget about vsync and try to have as high physical refresh rate as possible. On my old LCD, I play with native resolution 1680x1050 and it has only 60Hz refresh rate (can't stand smudgyness of lower resolutions so have to sacrifice 15Hz), nevertheless I don't even notice tearing at all. Only if deliberately try to see it