Killer Parka
Having owned a number of Patagonia's more 'casual' / less technical parkas (Thundercloud, Isthmus, Fitz Roy, etc.) I have to say the Stormshadow gets about everything right. For starters, it's roomy, providing adequate space for bulkier sub-layers and stowable items like gloves, beanies, water bottles, etc.. The GORE-TEX PFC-free membrane is surprisingly softer and quieter than what I've grown accustomed to. That being said, and having not yet tested it extreme lows, it appears tough, durable, and capable.
The only semi-cons are 1). the overall width / scale of the storm flap and 2). the interior lining of the coat, which isn't as forgiving or passable as some of Patagonia's other products.
Overall: 4.9/10. You won't be disappointed.