Warm, but not compact
I purchased two of these bags for an overnight on the PCT. I bought them because the price was great, but regretted it when they arrived. They were very warm, and reasonably lightweight, but they were just incredibly bulky compared to most other backpacking bags. The stuff sacks they come with are not compression bags and the bags themselves have no straps or ties, so they fill more than half a medium sized backpack on their own. I'm sure they'd be good for winter weather.