there is another advantage to having dual aileron servos...my 4 Star 60 in a decending L/H turn for a low, high speed pass...as I add power just before level off I hear a buzz and see my R/H aileron fluttering...throttle back to idle and do a climbing L/H turn to kill airspeed and set up for an emergency landing....the aircraft did not have the roll authority it should have had..but a nice landing was made and taxi to the pits was uneventful...investagation revealed a stripped R/H aileron servo.....the L/H aileron servo was ok..and that was enough to get me on the ground in one piece...I don't think that at that time I had the skill to get her back using just rudder.
So you see a dual aileron servo saved my Four Star 60 for more flights