John,

Another factor that enters is the "gear" ratio between the servo and the control surface. A servo wheel that rotates 60 deg in .2 seconds will move the surface at half that rate if the control horn is twice as long as the servo horn. If your servo horn is longer that the control horn, the surface moves faster than the servo.

This is very apparent with 3D setups which have extreme control throws. The surfaces move faster due to the gear ratio. This also accounts for the higher torque needed.

Bottom line; standard speed servos work just fine.

Tom