I feel like it needs to be buffed up. As written, it doesn´t even apply to CMD vs. said Maneuver. I can see why granting Improved X might be a bit too much, but why not just say it bypasses the AoO AS IF having Improved X, without granting the +2 bonus or qualifing for higher Feats? The AoO from Maneuvers is a pain in the ass, and still having to eat it hardly would seem to qualify as ´Maneuver Mastery´.