Im using the standard sbus servos for testing U300 and 400's. The S-U400 avoided Ian as it came from Tower hobbies not Huntsville and showed up at my door step today. Itz 98.6 oz/in @ 6.6 volts. Kinda weak compared to many generic digital servos of today but double of what a standard 148 would be back in the day. I have a digital HEXFLY HX-3225 servo that's 25 kg/cm . That translate to a servo with >3.5x the torque of this Futaba but they are not Sbus of course. A 25Kg /cm servo is something you might use ideally for the rudder of a high speed rc boat. But 98.6 would be right at a standard analog 1/4 scale futaba which has always been enough for us and obviously the larger planes @ 1/4 scale.