I started bowhunting in 70s,hunted self taught for 3 years before finally getting a deer in 1977. I've tried just about everything out there just to see what wooks and what don't-equipment geek. In my experience,The bigger cutting diameter you have within reason,as long as you have enough kinetic energy to assure complete pass thrus,the better. The last 24 deer I have shot left a bolld trail a blind man could follow but was completely uneccecary as they dropped while still in sight. In fact,I have even watched deer go back to chasing does or eating after a flinch! The bigger heads does 2 things-#1,cause massive wound for quickest bleed out,and #2,give that lil bit margin for error on questionable hits for most humane painless death. There's a lot of misconception about exactly how a deer dies from bleeding out. They lose blood flow to brain causing it to shut down.