I shot Thunderhead 85s for years but switched to 85 grain Slick Trick last year - the 'Tricks fly as close to field tips as any head I've used. I didn't get a chance to harvest a deer - but I did knock a huge hole in a gobbler with one !!
I've always stayed with the fixed blades. Shot the Thunderheads in 125 grain for yrs and killed many animals, quickly. Made the switch to carbons and the 100 grain Slick Trick Magnums last season and extremely happy with their results and killing ability.
I shoot Thunderhead 85 grain and they have not failed me yet. When I have tried others it was muzzy 3 blade and Rage 85grain 3 blade. Good Luck with your decison in broadhead choice.