I have just fitted a feathering Kiwiprop to my 2006 B33 and first indications are really good. The blades are composite, so anode corrosion is expected to be low. Performance astern is startling and something to get used to when manoeuvring in small spaces. I think I’m getting at least half a knot, possibly up to one knot extra ahead on engine and definite improvement under sail which has yet to be assessed but they do say one knot can be expected. Bit of noise when accelerating under engine which may be cavitation at the blade tips. When I’ve been out for longer, I’ll post again.