I tried a roll yesterday with my quad (X525 frame, 1.3kg, v2.5.3) using ACRO mode on the sprung toggle switch on my Tx. The short story is that the roll rate is very slow, far too slow to do a flip even a long run up and attempting a loop like a plane doesn't work well due to the very slow roll rate at full stick deflection.
So what can be done to keep the current sensitivity (relatively low) and controllability around the center of the sticks and yet give aggressive roll and pitch control at full stick deflection (fast enough to do a flip almost around the 'copters axis)?
Has anyone done acrobatics with APM2 & a 'copter, is it even possible? Videos on the 'net show some really nice aerobatic stuff (notably this: http://www.youtube.com/watch?v=c-gdw9kdgqA)
By default the rate is pretty slow. Acro_P is the term to crank up. It controls the rate at which your stick is converted to degrees a second. There is a ch6 tuning option for Acro P.
here's the logic:
4.5 is default
4.5 * 4500 (max stick deflection) = 20250 or 200 Degrees/second.
10 * 4500 = 45000 or 450°/s
We max out at 600°/s (I think) in the gyros.
Try and go a lot higher and let us know. We'll make it the default if you find a good speed.