RV6A O-320, and I just started working at Whirl Wind Propellers
I have an RV6A with 160hp O-320 and I just switched out the Sensenich aluminum prop for WW GA 200L 72" (Just started working at WW).
I will come back to this thread to link a more detailed report on the full experience and data collected soon, but initial thoughts:
The Sensenich was limited to 2600 rpm while the engine redline (and max power) is 2700 rpm; so the extra capability is nice. Since I try to operate my engine around 65% power, I only need the extra rpm when I fly over about 8,000 ft.
Installation: I am not the best handy-man, so installation took me longer than most probably would--but as people have already commented, the biggest annoyance is setting the pitch. I've heard that Sensenich has a solution for this although I haven't heard any reviews about it. It seems to me like it is for initial pitch only and if you want to re-pitch it I'm not sure if there's any aid. Overall I stumbled through the instructions, made notes on things to fix on the instructions (since I'll be doing all those updates now), and took about 4 hours to remove my aluminum prop, install my GA 200L, set the pitch 3 times before getting the blades the same, and wrapping it all up. (Pitch: 19.7?)
First flight: takeoff was overwhelmingly fun. Who knows for sure how much was placebo and how much was actual increased performance, but I lifted off the ground with the smoothest takeoff I've ever felt in that plane and took an elevator ride up to altitude in no time at all. It was at this point I realized the pitch was too low; when I leveled off it went straight past 2700 rpm.
I re-pitched it to 21.5? and that seemed to do the trick; I can barely get 2700 to 2710 rpm at sea level full rich wide open throttle (with leaning I may still be able to get close to 2700 around 8,000 ft -- will update with further testing).
Lighter, quieter, and looks nicer than the aluminum prop, and it feels like it performs smoother and better on both takeoff and cruise, but again: placebo may be taking over so I'll post the numbers when I do the real test flight.
Conclusion: you're starting off right by looking at composite props -- I'll never go back to aluminum. You certainly can't go wrong with this propeller, but I wish I could compare it to more than just aluminum to give a more complete comparison.