I have a Bobcat, and I can tell you if I do a loop at a high throttle, the elevator servos seem to stall a bit before responding. If I do a smilar loop but with less power, the elevator seems to respond better (IT also could be the thrust angle of the turbine).

That's why I am asking these questions. I think we need a data logger that can moniter servo movement, current per channel G force and speed. With this data, we can understand what's going on and may be pay less for the servos!!!!!