>>1148022Weight capacity, fully no-bullshit waterproof, stain resistant because it's expected you'll be lashing chunks of dead animal to the outside, frame designed for lashing shit to it if not outright removing the pack bag and using it as a hauling frame, a focus on quiet+abrasion resistant fabrics because it's expected you'll be going through shitty brush or dragging it along rocks.
Interestingly enough my Eberlestock Dragonfly ($350 fairly lightweight hunting pack bought some 9-10 years ago) has held up much better than my Eberlestock McMillan ($500 heavy tactical pack bought 6 years ago) despite being older and having about twice as many total days on it.