spitfires work great for me..a complete passthrough isn't all that important as long as you hit both lungs..too many people rely on a passthrough rather than hitting the vitals..the bigger the hole the the better..think about this: if an arrow with a 1 in. cutting diameter has a complete passthrough and sticks in the ground buried to the fletching,you've wasted all of that energy to make a 1 in. hole in the ground..if you shoot a mechanical with a2 in. cutting diameter and it hits the vitals but doesn't get a passthrough, then you've used that energy to push a 2 in. hole through 90 % of the animal..sorry, but i'll take the bigger entrance hole!!