A few years back, I produced a kit of Dick Mathis's Otto the Gyro. Allen Perret was still alive back then and helped me develop the rotor hub for the kit. He and I took the prototypes of the Gyro out and we looped them. This was all of the stunt capability they had. They were a blast to fly though. I had a .25 on mine and Allen had a .40.
I sold more of this kit than any other kit I ever produced.
Mike