Mechanical Heads for Quartering Shots

I shot Vortex mechanical heads in the mid to late 90's. Took quite a few animals with exellent blood trails, but got away from them based on deflection on quartering shots. Have been shooting fixed blade Muzzys ever since. Have any of you used the Shwacker mechanicals? What kind of luck are you having with them? What about quartering shots? Durability?

Thanks
Triple R

I don't use Mech, but Shwacker has done some pretty good test and they seem to work good on quartering away shots.