I presently have a Catto Prop on my RV-6. It replaced a Sterba Propeller that worked very well on the airplane, but I live in the Pacific Northwest where it rains alot. Flying the Sterba Prop in rain means throttling back to about 2100 RPMs to keep the rain from damaging the finish. I had hoped the Catto Propeller would eliminate the problem with rain, but it too was damaged while flying in the rain. I recently sent the prop to Catto for repair and installation of Rain Guard on the leading edge. I haven't flown it in the rain yet, so the jury is still out.
The wood propellers require constant re-torquing with weather changes. With the Catto Prop, you tighten it to specification and basically leave it alone, but I'll be checking on it from time to time.
Bob Severns