I do have a similar issue with the TGP and the MAV slewing.
I'm using my T.16000M throttle analog stick, and I tried different combinations, last test was with a fine tuning of ~45-50 on the saturation for both axes... no point.
It's seriously so nerve breaking that it pretty much renders the MAV useless to me
I wish there was a way to assign the mouse x/y for that.