Expo and less throws on your horns ... it's simple. : )

Regarding Slowing Down/Lowering Voltage: (scratches head)
Not sure how one would go about safely reducing voltage to servos as a way to slow them down ... or where you can buy a slower servo for aircraft ... you don't want a slow response in the servo. The only time you would use a servo-speed reduction module is for retracts and bay doors. Sounds like you just want less response out of the flight control surfaces.

- K