We got our first snow today so I layered my Marmot Kitzbuhel over my TNF Wind Wall fleece to take the kids to the bus stop, it was 32° with light snow flurries, but I felt warm. The bus was late, we spent 25 minutes in the cold but I felt very comfortable in my vest, mind you, I didn't have on any hats or gloves, but I didn't feel cold.
I plan to use the vest as an outer layer for cold weather aerobic sports, and as a mid-layer for skiing. The vest is well-made, its outside pockets are fleece-lined thus very warm, while the 1 inside pocket holds keys, change & a full-sized iPod. As a bonus, the fit is very flattering.