When I was doing extensive research on backpacks (tactical and civilian) a few years back I made a couple of important discoveries. 1) Nylon is stronger than polyester. 2) M.O.L.L.E. compatible bags don’t always fit genuine military gear. 3) Zippers are very important on a “tactical” bag. I prefer YKK brand and metal teeth. 4) A frame on a larger capacity backpack is a must (especially for carrying weight).
All of these observations came into consideration when I was choosing my bag. I settled on a Kelty Falcon 66 made of 500/1000D Nylon Kodra (Korean equivelant of Cordura) with YKK zippers and genuine M.O.L.L.E. specs. With these Yukon brand bags I’d probably purchase the duffel if it was a good price (and not sold out) but with a lack of information for all these specs I’d be a little hesitant to choose a backpack unless it was an everyday school/low impact work bag. Aesthetically they look cool, but functionally I’m not sure how they would hold up. Just one man’s opinion.