Arc'Teryx makes a mean soft shell, no doubt. They pay extra attention to details like stitch counts and anatomically correct articulation to ensure that fit and finish are at the head of the pack. The Gamma SV Hoody is their built-for-speed yet tough-as-nails alpine alternative.
The svelte 20oz Gamma is made from two different weights of soft shell material: Polartec Power Shield High Loft (ooh, so plush… stroke the monkey!) on the torso and shoulders for warmth and lighter-weight, less-bulky Polartec Power Shield everywhere else. The whole garment has a beautiful hand and cut, and the four-way stretch means it moves with a purpose.
Arc'Teryx made some bold design choices that end up working very well. The nonremovable (check out the hoodless Gamma AR if that's your bag) drop-away hood is helmet compatible, with a reinforced brim and a nifty hidden adjustment cord. There are two external zippered handwarmer pockets and an internal zippered small chest pocket. The hem is adjustable but the cuffs are not, and there are no pit zips, which doesn't much matter because the thinner material there vents perfectly well. The Gamma SV definitely puts the soft in soft shell.