I can't test this at the Apple Store, so could somebody with a Rev B Macbook Air do the following simple test for me (external mouse required): Use the trackpad to move over the dock area and observe the speed/smoothness of the magnification animation. Now do the same thing with an external mouse. Is the animation slower, the same, or faster in terms of speed/smoothness? I'm trying to figure out why the animation speed is different on the Air versus the MB/MBP even though they all use the same integrated graphics chip. The only thing different that I can think of is the trackpads so my hunch is that input tracking speed is the factor.