Both are great heads, but in all my testing I still have not found anything better than Muzzy. I think you will like both heads, but the Muzzys are a lot easier to work with. Thunderheads are sharper. If you shoot thunderheads on carbon arrows make sure you use the Ubar's. the are an adaptor that makes the fit between small diameter arrows and the broadheads better. This helps the heas hold onto it's blade better.

TAKE YOUR KIDS HUNTING AND YOU WON'T BE HUNTING FOR YOUR KIDS