Thanks for the update on this aircraft.
Regarding the aggressive roll rate on AP (which I agree is way too aggressive) I also see vertical fluctuations as well. In the turn the aircraft will drop 100FT or so then when it corrects it will oscillate a few times at 1000fpm up or down to recapture altitude as selected. Again this is excessive vertical behaviour. When turning the AP should make allowance for the turn and maintain altitude.
I will check this in 1.5.1 and report back.