We have a 4-bladed Variprop, the DF107, which is a 19" prop that Variprop cut down to 18" to fit the aperture in our 2006 PCS 40. We specified that propeller for that boat, which we had Pacific Seacraft build for us. We went to a 4-bladed prop for the reasons you mention: less cavitation in heavy weather, more surface area, etc. We were also sold on the ability to change the pitch of the Variprop while still in the water, without having to pull the boat out. The Pacific Seacraft factory worked with the Variprop distributor's rep to arrive at the appropriate propeller diameter and pitch for our boat. Once the boat was in the water we got the 3000 RPM redline at full throttle on our Yanmar 4JH4e, which indicates the pitch setting recommended by the prop rep was just right; we have not adjusted it since. In passing, I should mention that we had a two-bladed fixed (factory installed) on our 1983 PCS 37, and we used that for 23 years without a problem, either with maneuverability or in powering into head seas. Four blades may be more than you really need for the 37, based upon our experience. For the PCS 40, however, we consider four blades an absolute necessity. We've been happy with the Variprop and with the customer service they provided while the boat was being built. I'd suggest you discuss the issues you have with the Variprop rep and possibly with Pacific Seacraft. The guy we worked with was Rick Steadman at Varipropeller, USA (VariProp USA - The best feathering and folding propellers in the world!