Agree to disagree
I am sorry but I must reply to another review. I read a lot of reviews for a lot of products with a recurrent theme. This entails the critical review and analysis of a product when utilizing that said product outside of the realm of its (real) intended use. Obviously we are human and like to explore creatively in many different facets, but by using my years of experience mountaineering and powers of observation I can easily note that this is not a mountaineering and or technical pack and more simply a backpacking pack. Looking at the tool attachments and and overall design of the pack, it is not engineered for a lot of technical ice tools, crampons and heavy loads at that. The pack has a wide storage capacity meaning that it is much wider in the center of the pack, making a vertical ascension and descension difficult to maintain balance. Mountaineering packs act to distribute the weight from the top to the bottom to aid in vertical ascension and maintain counterbalance with the bodies alignment. Further more this pack has no gear slings built into it and does not have the heavy duty webbing noted in most mountaineering packs built today. Why I like the Z55? Well, the big kicker for me is I love dual access in all of my packs. If I don't have it I will literally tailor one myself. Why is that important to me? Well, I really love being able to find what I need when I want it, especially when there is a more emergent situation on the horizon. Aside from the dual access I like gregory webbing straps and hip belt, they just work for me. Anatomically, I am 5'10" about 165, and this pack in a size Large fits pretty good. I tried a medium and it was slightly to small, but the large is almost too big so I am in between. Do yourself a favor though if your serious, measure using gregory's measurement guide and you should at least have a good idea where you should be, keeping in mind all torsos were not created equal. Now what I don't like about this pack is I really don't like is the front pocket and its design. Another review disliked the capacity of this pack, but I think that you have to calculate this front pouch into the 55 liters. Unfortunately when loading the front pouch and placing some unsaid items compressed between this pouch and the body of the pack it can become quite bulky and creating and unbalanced load. For this I find this pack below my standard, but this might work well for someone of a different build than myself, or of course personal preference. As for Gregory, I really like their packs and the access points which are becoming more popular with many other manufacturers.