I have taken this bag into Chicago basin in Co and up into the pecos wilderness in New Mexico. Both trips it snowed after we arrived. I have the -20 bag and never had a poor nights sleep. I am very happy with the performance of the bag. The only draw back is that it is a little larger than I would like when packed. It takes up a sizable portion of my back pack. But after the first few nights when my camping partners were talking about getting cold I figured the extra bulk was woth it!