I flew the heck out of a Herr Little Extra using them. The little .074 hardly vibrated at all. Also ran them in a Herr Mustang using the same engine. I've even used the HS-55 as a throttle servo in a .40 sized airplane. (I would not use it on a control surface in that size of plane obviously) You might ask the guys over in the 1/2a forum what they use.