Ours is a conventional shaft-drive and when I replaced the fixed 3-blade with the Autostream 3 blade I picked up a little bit of vibration. I isn't bad, just noticable. I attribut it to the flat blades on the feathering prop. They don't have the twist like a fixed pitch does. Also, on our boat the water flow is not straight past the prop due to the angle of the shaft and the rise in the hull (fin-keel Catalina 42). I should think your sail drive should have a much better water flow angle past the prop. I did check to make sure I had all the blades in synch. It is easy to assemble it with one of the blades 1 gear tooth off which would cause the blade to have a different pitch than the others.

We have found the feathering prop isn't as efficient as our fixed-pitch. I've experimented with various pitches and our fuel consumption is a bit higher than before. I still like it because it is a sailboat after all . One other test we had was on a no-wind trip from the Columbia River to Vancouver Island accompanied by an identical boat with an Autoprop. We burned about 38 gallons of fuel and they used 34.