My .02 on this. Are you running 4 stroke or 2 stroke? The 2 strokes are so up and down on RPM every time you hit a little bump in the air that I would think the poor controller would have a hard time trying to keep up with constantly changing conditions. That coupled with the fact that the slightest bump of the manual controller can change the RPM so much it would have a very hard time keeping it set at XXX RPM. The electric motors in the ultralight prop are NOT heavy duty enough to be constantly used. I have gone through 5 motors between 2 different planes in the last 4 years. That being said, I would not be without my IFA prop, I absolutely love it and it has saved me more than once. When you take off in the morning and its 55 degrees outside, and when you return in the afternoon and its 90, you need to repitch that prop or your going to have nasty surprises in the performance of the plane.