I have a Logitech trackman marble on all of my machines, and I love it. However, I noticed that MS came out with one of their optical things that is almost exactly like the Logitech one. Has anyone tried one yet? Specifically, has anyone used one with quake? The Trackman doesn't pick up movements if I move it too fast and it sucks for quake. I'm wondering if the MS one will be any better. Jay