Gear Guide 2009: Big Agnes Mystic SL 15 Sleeping Bag Review

A three-season bag that is roomy and light, but not for side sleepers.

Light and Large

Like most Big Agnes bags, the Mystic dispenses with bottom-side insulation; your 20-by-72-inch pad, slipped into the integrated sleeve, does the job. The design saves weight, allowing Big Agnes to give the Mystic a huge 70-inch girth and semi-rectangular shape while still keeping it in the featherweight category for a true 15°F bag. (Peggy SL, pictured, is the women's version: $290, 2 lbs. 3 oz.)

Despite the roomy interior, testers stayed warm in sub-freezing temps thanks to high-loft 800-fill down, a mummy-style hood, and a free-hanging draft yoke that stopped even the hint of cold air from entering. The system saves about a pound from traditional bag/pad combos, but it doesn't work great for side sleepers (the hood doesn't roll with you), and you can't sit up inside the bag (so it's not for camp loungers). $390; 2 lbs. 7 oz.; 15°F