Kept me warm on Aconcagua, but zipper was a major problem--kept getting caught. No matter how good the bag, hard to stay warm when the side is open--had to wrap myself up like a burrito. A really good zipper would make this an outstanding bag.

I am an avid winter camper in Colorado and use the Wraith for my backcountry adventures. For me it came down to the MH or the Marmot Col EQ, in the end I chose the Mountain Hardwear because of the roomier cut for water bottles and more importantly changing capabilities on cold nights/mornings without sacrificing on dead air pockets. I am very satisfied with the MH bag. For it's size and loft I can still get it to a manageable size in my pack with a compression sack. My only complaint is that the zipper tends to get caught/stuck at times when trying to unzip or zip up quickly. However this seems to happen with my other down bag as well. I have had it out in single degree temps with below 0 wind chill and slept in a light base layer without a problem. I would highly recommend this product and look forward to using it on my trip to Denali in the spring.