ULTRALIGHT AND COMPRESSIBLE
Testers liked Big Agnes’s almost entirely recycled synthetic sack (the Skinny Fish; $180) just fine but were blown away by the down-filled Zirkel’s warmth-to-packability ratio. Like all the company’s bags, the Zirkel integrates the pad right into the bag via a sleeve on the underside, which, in addition to making it impossible to slide off your pad, also saves weight. And it helps that it’s stuffed with ultra-lofty (and expensive) 800-fill down, which requires fewer feathers to get the same temperature rating. The only downside: It requires a mummy-shaped pad, and the ones Big Agnes makes will set you back another $43 to $100. 20°, 2.2 lbs; bigagnes.com