At 900 fill goose down, the Marmot Quasar down jacket is my go-to mid-layer for warmth, pack ability and weight. Its ultra-light weighing in at less than 1 pound, and one of the most convenient features is that it packs into its own pocket. Its literally the size of half a Nalgene bottle! I can take this anywhere and know I’ll be plenty warm if the need arises. I also really like the flexibility I have with my arms in this jacket due to Angel Wing Movement TM feature, which is intended to allow full range of motion of the arms without the down jacket riding up.