I live and work in Yellowstone and like camping with my hammock. Hammocks tend to make sleeping bags lots colder so I bought this 0 degree bag and could not be happier! Nice and warm on a 30 deg night, very comfortable and it fits great! Btw I am 6'8 tall 290 lbs.
I used the bag late September in Yellowstone. Temperatures went down to 25F. I was perfectly cozy in the bag (even too warm at times). The bag is wide enough to let you move (I'm a side sleeper). Foot box is great.
I am 6'3 170 lbs and have more that enough room in this bag. I have used it about 4 time in below 0 degree conditions and it keeps you nice and toasty.