Shot a deer last year with a 53@29 longbow and a 160 snuffer (total arrow about 550gr.). Hit lungs, ribs, liver and the arrow never even slowed down. I've also had bad penetration with a 145 snuffer when the deer spun around and ran at the shot. Hit him angling down into the kidneys. Never found any blood, but saw the deer later in the season so he was okay.
The moral is, make good shots and you'll be fine with the snuffer. The Woodsmans I ordered a year or so ago had such quality control issues that I won't bother with them again.