Lightest and Warmest
i chose the mountain hardwear phantom over the mountain hardwear sub zero for two reasons:
1. it's warmer with 800 fill vs. 650 for the sub zero.
2. it's lighter at 15oz (440g) vs. the sub zero 1lb 11oz (765g).
i am 5'10 with 31 inch waist and i even went a step further and went for a size small. it's perfect, but any smaller and it would be too small. it's light and super warm. i like the shortness of it in case i need to wear a harness however some might feel it's too short. it packs down into a nice little package for packing on the skin up. AND the fleece lined pockets are a very nice supprise luxury for a superlight jacket.