For the size it may be hard to beat the torque and speed combination this servo offers. My helicopter is a 450 TRex clone and while I don't do extreme aerobatics it was quite an improvement from the stock servos. Some of the control horns are a little flexy/flimsy but I used the one that is circular in shape and, for me, it seems solid enough to do the job. There may be other horns available from Futaba or other vendors, though I haven't researched it. I would recommend this servo.
1.888.739.4354
S3156 
