The closer the weight of your pack is to your back including above you is going to make the pack ride better.
Right, that's elemental. I just wondered about the closeness to the head thing as that would drive me - and I imagine anyone that wasn't afflicted with severe Kyphosis, absolutely nuts, especially when ascending steep terrain.
It sounds like that's easily remedied though by tweaking the bayonets.
Other than some minor ventilation issues, it looks like a very cool, very no-nonsense pack.
