We have a Bavaria 40 Ocean CC with a 50hp Volvo w/ saildrive and have powered into some nasty winds, chop, etc...and never felt underpowered. Pushed like a champ - I also feel our kiwi prop added to the engines ability to push through those conditions. We ownen another boat prior that I felt was underpowered and you know it when you need it most. It is not a good feeling. Luckily with our Bav 50hp I never had that feeling even once. If you can get an extra 10hp go for it. It might make a difference at the times you might not be thinking of right now.