I shoot roughly 50# these days and just for that reason I will not, in good conscience, shoot any mechanical head, 40ke or not. Probably the Muzzy is as good a head as any so why not stay with them. Honestly, if he can tune his equipment and shoot to where he is aiming a good set of sharp blades get the job done, no matter what head those blades are on. Getting good arrow flight is the trick to keep all the momentum behind the head, driving those blades as deeply as possible.

To that end there is nothing magical about any broadhead. They all kill by the same means----internal hemorhage.