I am in favor of a single bolt hub. I don't have a lot of equipment available and for me, I need a straight hole. I am lucky that when I purchase a propeller from Airwild, it is the correct hole size for my Brison 3.2 and I don't have to do anything. I have ruined several propellers by drilling the holes in the wrong place. Here again, I am not the most mechanically inclined person you will ever see. I can understand the theory, but application I know is my shortcoming.