I am not a big Muzzy fan. I know there are lots of things about them that are good, but I think there are many other, superior heads out there. I am really happy with my QAD Exodus, for example. Exodus blades are .040" thick, while Muzzys are .027" That's significant. The ferrule of the Exodus is also much stouter and stronger. Sure Muzzys will kill animals, but again, there are much better heads available.
Like was said before they are pretty much like the Blitz which is what I use to shoot still have a few Laying around and the Blitz's were awesome. Not sure if its true or not but from what I heard someone that was involved in the blitz wentto work for muzzy after rage bought Rocky mountain so I'm guessing its pretty much the same head. I still use the blitz for deer and they do make a hell of a hole