Pack selection – Osprey Atmos 65, Granite Gear Escape AC, or GG Nimbus Meridian

Is REI your only local store? If so, you can order the GG Escape online from them (and the Nimbus Trace 62 if you want to try that), have it delivered to the store, pick it up and fit it and try it out there. If it doesn't work return the pack(s) before even going home. They have a few GG packs, they just don't stock them in-store.

I haven't worn any of those packs, but I do have an older model Osprey Aether 60 which I really like. It supports weight really well.

I'd second what Charles said about REI- only way to know what works for you is to try out the pack.

This aside, I'd lean toward one of the Granite Gear packs largely because of the hipbelt. For me, the hipbelts on the Atmos and Exos just don't seem to work. The hipbelt and suspension on the Aether 60 is brilliant, though the pack is heavier than most of us here want.

For heavier loads (35+) I'd go with the GG Nimbus Meridian or Nimbus Trace. For loads under that I'd lean towards the Escape AC, Blaze AC or Crown VC. Personally, feature- and weight-wise I'd prefer the Blaze AC or Crown VC over the Escape AC but that's more a matter of what you like. The AC packs seem to hug my lower back a bit better than the Nimbus packs- I think the curve on the backpanel has more of a pronounced curve.

Good luck!