I have tested just about every head available. By every measure the Ace standard 160 comes out with the very best. Very tough, sharpens very easily whether file or gadget method, mount true, hold the edge for a long time and through the animal, no noise or wind plain when mounted true, zip through bone like butter, blood trails as good as any three blade (Except snuffers), and econimical (low cost and you can't bust em, ruined 2 grizzly el grandes, many ribbies, can;t break the ace). And most important- Made in the USA
I guess I give them two thumbs up