"This is an amazing pack. Incredibly light (16 oz) the G4 it’s the perfect pack for any ultra lighter. The construction uses a light 70 denier 2.2 oz nylon that weighs next to nothing. The pack also saves weight by not including a suspension or padding in the shoulders straps and waist belt. Instead, you stuff articles of clothing you won’t be using for padding. (I put in a pair of sock liners I use to sleep in and my sleeping boxers and cap.) It’s not as good as foam, but it saves weight.
The pack performs well on the trail if you keep the weight down. I’ve found I can’t use it for anything more than 3 night trips without it weighing so much I feel it in the shoulders. The goal is a weight below 30 pounds. I also roll up my Z-rest and insert that into the body of the pack to form a frame. I find it does a decent job of keeping the weight on the hips and provides padding on the back. The other thing is this: be careful of branches, sharp rocks and the like. The nylon is not very abrasion or puncture resistant.
All in all this is a good pack to buy if you are a lightweight or ultralight hiker. IT weighs next to nothing and handles most trips. I plan on taking it on my AT thru-hike, where I will be replenishing every 3 days or so."