Love performance bags but balk at their performance price? This synthetic-fill bag gives you many of the technical features and warmth of pricier down models at a fraction of the cost. “I carried this bag up to Camp 2 on Mustagh Ata in China and slept comfortably right down to 0°F,” our tester says. “One night we accidently left a tent vent open and I woke up with 3 inches of snow on my torso, but I didn’t feel remotely damp or chilled.” Designers performed a few magic tricks to make this work. They eschewed traditional sewing techniques in favor of welding the insulation directly to the shell, which eliminates seams and potential cold spots. Next, they employed their proprietary Thermal.Q insulation, which uses short polyester strands of varying diameters (thin ones trap warmth and thick ones increase loft). And although compressibility is usually a trade-off for synthetics, this bag’s welded construction reduces bulk by eliminating the need for overlap found with traditional shingle construction. Our tester says he was shocked at how small he could squish this bag—“down to soccer-ball-size”—with the included compression sack. “It’s on par with some down bags in this temperature range,” he notes. The combination of a wide and puffy draft tube along the zipper, a plush draft collar, and a smart drawcord system (the dual drawcords feed through the same cordlock so there’s no fumbling) eliminate drafts and gaps. After a week in Montana’s Beartooth Mountains, one tester said: “I never felt a draft once I battened down the hatches, even when I slept outside sans tent and woke up with an inch of snow on the bag.” Despite the precip, the ultralight, 15-denier, DWR-treated shell kept him perfectly dry. $280; 3 lbs. 4 oz.; 0°F; mountainhardwear.comWelded Lamina™ construction with Thermic Micro™ for outstanding compressibility and durability, the UltraLamina is an excellent choice for damp, cold conditions. Engineered to be lightest and warmest synthetic bags available for year-round all-conditions use.