Hiya, I've been thinking for a while now about getting an arc haul. For the last 8 years Ive been using an Exos 46. I know there are mixed views on how much the vented back actually ventilates but I really like it. Hence the interest in the Arc Haul rather than any of the packs that sit directly on the back. I've seen some people saying that the cuben fibre makes an annoying crinkly noise and I wondered - can you hear that when walking or only when packing and unpacking? If it's noisy when walking I'd go for the dyneema but I like the waterproof quality of the cuben. Any thoughts on this please? My reasons for upgrading are that I'd like a little bit more space, a little less weight and the Exos doesn't meet my other main two criterion which are to be able to grab my water bottle on the move and bigger hip belt pockets to fit my massive iPhone. I don't like the look of the new Osprey Lumina just reviewed because no hip pockets and fitting aftermarket ones looks awkward. Exos 56 is also possible.