In my opinion - and keep squarely in mind that it is my opinion, based only on my own use - forget the Osprey Exos packs (and the Talon, for that matter.) The suspension is not adequately supportive for a load of 35 pounds. Will it carry it? Yes. But for me, the hipbelt started to collapse at 30 pounds, wouldn't stay put, and wouldn't keep the load off my shoulders. You should be aware, however, that I've read reviews by others who claim it carries 40 pounds comfortably.

The Atmos would certainly work; I've used it at 30, and it never missed a beat. However, I'm just not a big fan of trampoline style suspensions. My current favorite pack (at least this week) is the Deuter ACT Zero 50+15. It's got a good, sturdy hipbelt, two aluminum X-frame stays, and well padded shoulder straps; at 30 pounds, the load never budged: it stayed centered on my hips, and I could shift weight between my shoulders and hips as I chose.

Another good Osprey pack is the Volt (60 or 75 liter versions available.) Good, sturdy suspension easily able to carry 35 pounds comfortably. I've used it, and really liked it - but there's no way I need 60 liter capacity; even my winter long-weekend load barely gets into the 15 liter extension collar on my 50+15 liter pack. However, if you can fill it up, it's a great pack.

The weights: Atmos and Volt are both right at 4 pounds, Deuter is 3.25 or so, and Exos is 2.5.