It's all about preference, and what you are trying to accomplish.
Don't let the speed demons try to feed you the lighter the better garbage. I likethem heavy,my FOC is 21%, total arrow weight 543 grains, I shoot a 220 grain Muzzy Phantom cut on contact my draw weight is 58 pounds. I bust through deer and hogs with ease. I also like the fact that the heavy broad heads are thicker. The Muzzy's are .040 thick.