1. No gimmicks here. The North Face's new X-Radial suspension is the real deal. The secret is a lightweight aluminum, X-shaped frame that's reinforced on the top and bottom to deal with heavy loads (up to 55 pounds) and actually pivots at the center of the X, which means the pack moves along with your body as you stride forward, instead of just sticking to your back.

2. The Primero forgoes all the extra heft of complex mesh suspension systems and instead relies on simple injection-molded EVA foam padding—like the stuff used to make Crocs—with vents on the back and lumbar regions. While not as airy as the best mesh systems, the EVA felt comfy on nearly every tester's back—and doesn't suck up any back sweat (or odors).

3. It's virtually waterproof. The hood and sleeping-bag compartment are both made with waterproof fabric and welded seams, and the rest of the pack is cut from highly water-resistant material. Everything we crammed in the 3,650-cubic-inch (60-liter) Primero stayed dry, even in a downpour. Need more room? There are 65-, 70-, and 85-liter versions. The 65 is women-specific.

5 lbs; $270 thenorthface.com