Well, consider me a robot then, heh. I myself am well aware of how absurd it sounds, but the fact remains. To be honest, I think it's not so much about sensitivity per se, as it is about the feeling of better tracking. I can assume that it has something to do with the calibration of the mouse sensor or a feature of raw accel itself. My money's on the latter. Anyway, yesterday I played for about half an hour on each value, and got the best track on this one.
P.S.: I have no luck at all with "your sensitivities" (it was a joke, but I'm not sure how the translator translated it) XD. For some reason it's very difficult to change from one to the other and feel things that just can't be felt. Meh.