It really depends on what arrow you're using. A stiff arrow can take a heavier(really demands)head. A light weight flexible arrow demands a lesser weight head. It's a balancing act. You MUST match your equipment. It's not a question of do I have to... it's what am I working with? Go to the Easton Arrow Selection Chart and start from there. If you already have your arrows... plug that data in. If you don't, play with the numbers and make a choice.