I got this bag after having 3 other ones. I bought it over the lighter REI bag because it is roomier inside, and I tend to sleep on my side with legs pulled up. I used it on a winter bicycle trip from San Diego to St. Augustine. I am a cold sleeper, cold feet etc, but my feel always warmed up in this bag. I slept fine with some underlayers on in 15 degree weather. It is well built, and the zipper is nearly snagproof. On many warmer nights, I simply used it as a blanket. I read many positive reviews of this bag, and I was not disappointed!