DUC "almost constant speed" propellor

[gossend]

Anyone have any experience with the DUC ground-adjustable carbon fiber props? They claim almost constant speed performance over a wide speed range. They say they achieve this not through blade flexing, as has been tried before with some success, but "aerodynamically".
I recently saw some inflight test data that seems to back that up.
Not clear how they do it.
Has anyone had experience with it?
Craig, what do you say?

 

[saintlfd]

Check videos from Sting Flight on You Tube; also search the forum SportPilotTalk for the experience of one pilot with the Duc on his Sting Sport.
As I recall, he was favorably impressed.
D