David G.wrote a review of Osprey Packs Atmos 50 Backpack - 2800-3200cu in on October 11, 2013
Familiarity: I've used it once or twice and have initial impressions
I purchased the Atmos 50 form the four day hike to Machu Picchu. It's a great, comfortable, and very adjustable pack. ...and a life time warranty. I have no complaints. I also purchased the medium cover, which is too small for just the pack, but was ideal for a full 50L pack with a mat. It kept all of my stuff dry including my SLR.