Other Thoughts: This bag is one of the most useful pieces of gear you can own in the Southeast. It's a great temp rating for most of the trips I do - 25-65 degrees.. It packs into such a tiny, light package, I stuff it in a small waterproof sack with a hammock when solo camping. I'm cold-natured so I need a liner when it gets below freezing. Tip: the less you keep the down compressed the longer it'll last. When you're out camping with it, pull it out of the stuff sack 30 minutes before you go to bed & let the down decompress. You'll get warm faster. When you get back, store it in the LARGE bag that comes with it, or hang it in a dry safe place.

Other Thoughts: Yeah, the UltraLite is awesome. Thanks, Jeff! I've lusted after this bag ever since Jeff let me borrow his. If you have never used a 850 fill down bag, it's impossible to describe with words how warm and light it is. You can also use the UltraLite 20 when it is not very cold. This is definitely the bag to get down to 20 degrees if you don't have any concerns about getting your bag wet. The UltraLite can handle some moisture, but down doesn't work well when wet and takes forever to dry (= won't dry for the rest of your trip if it gets soaked through).