The cubed pillows surrounding you, and especially with the hood on, make you look like a complete buffoon. That said, you will be the warmest and least encumbered buffoon to tromp around in the sub-zero. Rab did everything they could to make this jacket light, including stretchy wrist collars instead of velcro. I would have preferred velcro. The electric orange might as well be used for highway markers, as you can spot me from space. The Pertex behaves like most other ultra-light dwr nylons. It weights nothing, and really isn't nearly as ripstop as they make you believe. I did easily tear a nice little hole in the back, but that's the trade-off for weight. I'm 5'9", 150 pounds, and the medium is roomy enough for a couple layers underneath.
I've had both the Mountain Hardware Sub Zero and Phantom. This jacket is a solid upgrade from the Phantom, and I will never look back.
Just be warned, if you put the hood on, you'll be warm, but no one will take you serious.