Our take Warm. Light. Comfortable. Every quality you want in a sleeping bag, and the Magma nails them all. And it adds one more you don't usually find when you get everything else you want: affordable. "This is the bag I'd buy if I could only have one," says Editor-in-Chief Dennis Lewon, who used the Magma during five days of soggy, chilly hiking in Colombia. "And the liner is uncommonly soft, which I didn't know I cared about until I felt it."
The details REI's direct-to-consumer model allows it to use premium ingredients like 850-fill goose down and 15-denier Pertex Quantum ripstop nylon. And the bag incorporates effective construction like variable baffle spacing, which is a fancy way of saying the smaller, warmer baffles are near important areas like your torso, and the larger baffles are around your legs. The result is a 10 degree F bag that's in the same weight and price class as some 20 degree F models. "It's like getting free warmth," Lewon says. Caveat: Cold sleepers will want to add a puffy if they're going to take this all the way down to the temp rating.
Trail cred Unlike most lightweight bags, the Magma doesn't have a coffin-tight cut. Its shoulder circumference is right at the 60-inch sweet spot, and footbox space is above average. "On a long winter night, the extra room makes tent life significantly better," says contributing editor Will Rochfort. Bonus: The new zipper head cover—with a triangular plastic piece that prevents fabric from getting caught—greatly reduces snags (and potential damage) compared to other bags with such wispy materials.
The women's Magma is not quite as warm and light (it's rated to 17 degrees F and weighs 6 ounces more), but our testers say it's the best women's bag in its class.