What Nick says is true if you make a direct comparison between the two aircraft. However, it is my understanding that the Pathfinder uses an existing airframe to prove the concept not to modify all of the Seahawks. But then again I have been wrong before
The Cheyenne was in fact a compound helicopter and although it had problems in the dynamic system it flew quite well with the propeller providing the thrust.
I personally believe that when you turn a helicopter into an Autogyro it takes on some of the bad characteristics of an Autogyro. That is when the wings are taking the load the main rotor is in low pitch. If the pilot moves the cyclic to maneuver the aircraft the advancing blade will go into negative pitch. The blades have a negative twist and with this twist the blades have a root angle of say seven degrees and the tip is at a neutral pitch. Movement of the controls when in Autogyro mode can result in disaster. IMHO.
