"This thing isn't a sleeping bag, it's a bomb shelter," said one tester after spending a night out in cold rain with only the Banshee for protection. Credit the waterproof/breathable Conduit fabric, welded seams, and generous overlapping zipper flaps, which protect 800-fill down. The result is a compact bag with real 0°F warmth (for normal sleepers in midweight long johns) and near-total stormproofing (there's no protection for the face).
After that downpour, we packed it up with the cover fabric still soaked, and when we pulled it out the next day it had lost very little loft. The cut is just roomy enough for puffy layers. Downsides: The Conduit fabric gets a little steamy on mild nights, and the storm flaps cause occasional zipper snags. $500; 3 lbs. 6 oz.; 0°F