I've shot both 3 and 4 blad muzzy's as well as 4 blade heads in other brands. Both heads provide excellent penetration, however, if your bow is not tuned correctly penetration will be affected. Cutting diameter is a small issue to me. I prefer the 4-blades in everything I shoot because more blades = more sutting surface = more tissue damage.I also like a more small profile head. Good luck.