I reserve my larger mech heads (1.5"&^) for evening hunts when I'll be tracking solo. When using such a headI will only take a close up high percentage shot, anything else get's a pass. I've only shot under these circumstances once and the plan worked.

Besides that scenario I stick with fixed heads.
I once had a shot go sour on a deflecting limband the broadhead & arrow hung up along the outside of the ribcage near the heart area. The 4 bladed fixed blade worked it's magic as the deer ran off and wound up slicing enough veins & such to getter done. It wasn't a short tracking job, but the niner was mine.
Had it been a mech head it would have just popped right back out.
This is one of the main reasonsI primarily stick to fixed blades, one more factor working in my favor.I need all the helpI can get!