I currently have a boat with a sail drive and had a conventional shaft on the previous one. The sail drive is proving to be quieter and smoother when motoring, no question based on my experiences. There is information to indicate the sail drive has less drag. Having the propeller
parallel versus inclined also seems more efficient. The down side is keeping after the corrosion
. My shaft just need a few minutes to replace the zincs either under water or when hauled. The Volvo
sail drive I have know requires removing the the prop to replace the zinc and so for me it is a haul out
. I won't do it under water just because I don't want to drop something small and vital into the goo. The cost of hanging the boat for an hour is about the same as hiring a diver so out we go. It does allow for a good bottom survey
and scrub so it isn't all bad. Based on by experience, I would go for the sail drive in the future if it was a tie breaker between boats.