Light enough for fastpacking, comfortable under a big load for luxe-packing. That’s our tester’s conclusion after she carried the women’s version (the ACT Zero 45+15) on Yosemite’s High Sierra Loop. She dubbed the load transfer superb. “My shoulders were never chafed or tired,” she says, “and my back never got sore.” She hiked with a 45-pound load for seven days on the Yosemite trip and says the pack’s crossed aluminum stays provide superior support with torsional flex, making for a supremely comfortable all-day carry. The foam hipbelt and padded shoulder straps deliver excellent cushioning without bulk or undue weight. She also applauded the pack’s ability to balance awkward loads.
“Even when it was stuffed, I never got that Leaning Tower of Pisa effect,” she says. A long collar extends (that’s the +15) to accommodate bulky loads like bear canisters and family-size tents. You also get exceptional breathability for a suspension that sits close to your back: Hollow-chamber foam lines the backpanel and helps to “pump” air away from your body. Our favorite feature? The removable lid converts into a 15-liter summit pack that came in handy for short dayhikes from basecamp. The torso adjusts from 15 to 21 inches for a dialed fit. $185; 3 lbs. 7 oz.; 50 liters; 1 size each for men and women; deuter.com
Deuter's answer for the lightweight trekker who doesn't want to sacrifice all the features.