Steve wrote a review of MontBell U.L. Super Spiral Hugger #1 Down Sleeping Bag: 15 Degree on December 16, 2010
I was reluctant to spend this much on a bag. But, after having used it on a recent backpacking trip, I have to say I love it. The low weight and small packed size allowed me to fit a few things in my bag that I might have foregone otherwise. And, this particular trip turned into a very cold overnight. Yet, I stayed warm and toasty.
I didn't think I would like the mummy shape, but I had plenty of room. And the bag does stretch quite a bit so I could sit up and cross my legs and even get dressed without having to venture out of the bag into the cold morning air.
The only negatives might be that this bag is very warm...probably not good for warmer nights. Also, the zipper tends to get stuck in the draft tube. You have to be careful. So, this wouldn't be a good bag for someone that doesn't take good care of their equipment.
The stuff sack that comes with the bag is long and thin, sort of the size of a full-size loaf of sliced bread. And, it's make of the same material as the bag so it may not be all that waterproof. Instead I used a compression dry sack and got the bag down to the size of a large canteloupe. Finding a compression sack the right size can be a challenge.