Charlie,
Since most of us don't fly Scale Autogyro's what is scale speed ?..

If you build light and have a good wind you can fly slower. If I can land with zero landing roll , I say I was flying a good scale speed. Some manufactures of full size Autogryos are trying to go fast unlike the the Autogyro's of the 30's.
I personally like slow, some like fast and wild. I have done loops and rolls and like dead engine landings from up high.

Come on down to Lakeland in February and we will do some SLOW flight.

Jim