I noticed a problem when using ML: when I tried to focus normally (not using LiveView) using a focus point other than the middle focus point, the camera could not lock the focus. When I turned off the camera (so ML was deactivated) and tried again, focus was working fine.
I have not tried this again, so it could be a one-time problem, but maybe someone else can try to reproduce?
Anyway for the rest ML was working fine, the magic zoom is great (although it flickers quite a lot).