Deuter's ACT ZERO 50+15 received Outside Magazine's Gear of the Year Award for 2011 this past week. It was also reviewed in the May issue of Backpacker as their second highest rated weekend pack; it received a 4.6 on a 5 point scale. At 3 lbs. 5 oz. this pack offers a lightweight pack option that functions more like a load carrier with lots of standard features you'd expect in a heavier pack. Adjustable torso length, top pocket, ice axe holder, mesh water bottle holders, hydration bag pocket, large front panel mesh pocket and side compression straps make for a pack that you'll be comfortable with on a weekend outing or even a longer trek.
We've grown especially attached to Deuter's approach on suspension systems. The ACT ZERO features the AIRCONTACT system with Vari-Quick. With beefy foam straps in the back, hip, and shoulders you be surprised by how comfortable it is to carry large loads. The attention to ventilating your back adds significantly to the comfort effect over the long haul. We've tested Deuter's AirContact suspension out on several backpacking trips now and have been very impressed.
A slim/slender "SL" version-- the ACT ZERO 45 + 15 -- is available in pine moss green and is an ounce lighter. While advertised as the women's specific version of the ACT ZERO, the 45+15 is really suitable for anyone who doesn't have a large frame. We expect that this version of the pack will become especially popular with boy scouts and teenagers in general.
Note that while this pack boasts a lot of load carrying capacity, the external strap options do not provide many means for attaching pads, tents or other large pieces of gear.