I belive that every hunter should use what ever they feel is best for them.
Both have advantages & disadavantages.
I have used both.
Just let me say that most but not all mechanical broads that fail that I have personaly seen are people that are speed freaks shooting light weight arrows at high speeds so there is almost no KE at the far end.
Fact: It takes more KE for a mechanical to pass thru than a open head.
Fact: You should not use a mechanical head if you dought it will work with your set up as you will never trust it to work.
Fact: most but not all mechanical broad manufactures suggest an arrow weight of at least 485gr with broad head & a bow drawing at least 55 lb.