I use Mech' s exclusively for two reasons. 1- they are more accurate, and I feel shot placement is far more important than whether you shoot fixed or mech. 2- there are no exposed blades, so they are safer.

The only drawback, in my book, is you do pay a price with penetration. No mech cuts as well as a sharp fixed blade. Were I hunting bigger game than deer, I would be using Muzzy' s.