REI Downtime 0

I've owned this bag since 1998 and it is still my most comfortable bag. This bag is fairly roomy which helps me sleep better. 

I also have a Marmot Sawtooth 20 which is a a quality bag as well, but not as roomy and therefore I don't sleep in it as well.

The REI Down Time 0 degree bag is comfortable to below its rating as I have used it on Mt Rainier for several nights and also on a winter mountaineering trip in January. On the colder nights I put on a pair of wool socks and polypro long underwear and was plenty warm. 

It's not the best bag out there at this temp rating but I'm very happy with it for the price I paid.

The old addage is true: "you get what you pay for." For $200, you are not getting much in the way of a sleeping bag. First off, the quality is not there. I have had to send this bag back to REI twice for repair (the first time, the seams on the draft tube fell apart. The second time, the zipper broke). Second off, this is not a "true" 0 degree bag. I would rate it at about 20 degress. If your looking for a good 0 degree down bag, I would highly recomend The Sierra Designs "Clyde" down bag which is superbly made and only cost about $25 dollars more (on sale). Retail is about $275.

This is a cheap bag you can bang around without too much guilt. It is rated at 0F but is really about a 10F - 20F bag, and I sleep warm. If you take it out in -0F weather, take liners and warm clothes. I bought this bag in 95-96. REI has upgraded these bags for 96-97, and they look better.