I have a friend who says by replaceing his 3 bladed aluminum prop with a 4 bladed stainless, he's gained 20% more power and milage. I think he's just saying this because of his $500 investment and is too proud to say otherwise. I think that while there may be a sight improvement, 20% is physically impossible.
What are your expereinces with this comparison? I'm sure there are other threads that hash this out, but I'd like something fresh.