if you are asking for opinions then heres mine. don't waste your money on the nap heads. yes don't get me wrong . they are excellant heads, but
they do require alot to open compared to what i use. i use the rocket hammerheads and the need half the energy to open and have 3/4 of an inch more cutting width than spitfires. just my opinion but the hammerheads i have used on deer have dropped all my deer within 50 yards. they do not go very far with a 2" hole in each side. as far as bone splitting how about through the front shoulder and out the rear hind hip. devastating. also by the way the nap spitfires cost about $30 for three and the hammerheads are $20 for three. just my preference and good hunting