IME, Some common sense is required with this UL gear. Will it be as bulletproof as the heavy packs- heck no. Is it durable and UL at the same time as long as you don't abuse it- Aron says it is and I believe him.
UL gear always comes with some kind of a tradeoff. No doubt this pack isn't for everyone but it sounds like Kifaru made on heck of an effort.