I also have used the muzzy and the thunderheads almost exclusively in non-tradional bows. Never had a single problem. I'd sharpen the trocar for a stickbow on the muzzy, and just sharpen to a good point on the thunderheads.
They're both solid heads.
I prefer the muzzy for a four blade, and the thunderhead for a three blade.
The muzzy 3 blade ferrule is weaker than the 4 blade because the cutout for the blades is wider on teh 3 blade due to the way the blades overlap when teh head is assembled. I had one break on a rock. 4 blade or thunderhead ferrules seem pretty bulletproof.
Did anyone here mention yet that muzzy and thunderheads are some of the only replaceable blade heads that still come in a 6 pack and can be had for around $30?
I refuse to spend big money on a head when a cheap one is perfectly good, and when a sharpened rock would work too.
With all this said, I'm considering switching to all COC heads for all my setups. I shoudl just buy a case of WW or something ...