The Shocking Blue is an exceptionally high quality -10 degree down sleeping bag designed for cold weather expeditions. The bag has 850-fill down, 91 custom cut fabric panels and baffles, a massively comfortable foot box, and a super warm neck baffle. The cut is wide in the upper body to accommodate broad shoulders or down clothing; the bag is ideal for extended trips, expeditions, or fast and light trips in cold conditions. The Shocking Blue is more comfortable and warmer than other bags we've reviewed in this class.
People looking to save weight should consider a slimmer bag without expeditions features like a large toe box and hood. The most versatile winter bag tested here is Feathered Friends Snowbunting ($550, 43 oz). The Western Mountaineering Antelope MF ($470, 39 oz) is cheaper, lighter, and less warm.