RE: 2 blade or 4?
Go with the 3 blade Magnus Snuffer 1 1/4 or 1 5/16 cutting diameter. More cutting diameter and its a mean head. I get pass throughs on 90% to 95% of my animals and I'm shooting a recurve. Trust me you will like them. Shoot a few of them once and see how they fly for you and if they make any noise in flight. If all checks out well I'd go with them if I was you. All the Magnus heads I think are good heads, just some have bigger cutting diameter's then the others.