i beg to differ... with junky weak cheap fins, you will not get the performance that you should as compared to the Marzo's i just got. so fins are just not fins.
I agree, you can "push off" a stiffer fin (100% fiberglass) better in weak waves, but main difference I've noticed is in "cant". Super canted fins need to the board to be put heavy on the rail in order not to slow it down. That's why I generally prefer more vertical fins on slower waves - they glide better. Some people say it's all too negligible to matter, but when you're grovelling, everything adds up
cant doesn't mean a damn thing if your fin is too soft to maintain it's shape against the pressure of a turn.