This jacket is nearly impossible to beat for the weight to warmth ratio. It's impressively warm and kept me plenty insulated on day pushes in the Tetons and the Lone Peak Cirque. Also, it stuffs into its own pocket and can easily be clipped to your harness or stuffed in your pack out of the way. If you want a little more warmth you could opt for the hooded version or check out the Thermawrap from Montbell. If speed is your game however and you want that extra bit of protection from what the mountains will throw at you, check out the Nano pullover.