Two compositions, both comprised of several 720p, ProRes clips, all exactly the same length. In both, clips are being tracked by two points. One composition tracks quickly - the tracker zips right along; while in the other, the tracker zips along for about 1/3 of the length of the clips, then slows to a plodding frame-by-frame pace.
I've turned off the motion path display. What makes the tracker go fast or slow? What could possibly be different about these pieces of footage? One comp has 9 layers, one has 12.