One guy at my club got away with standard Futaba servos in his Do(43oz I think)and 2/56 rods without a problem. However, he never throttled up unless hovering. He also had all hinge gaps sealed. I use nothing but HS635 Karbonites,4/40 rods & 6V & seal the gaps too. Never had a speck of trouble over 100 flights-no slop yet either. MG's will give you slop over time.