OK- first off this bag is WAY roomier than I anticipated. I'm 6'1 225 lbs. and I sleep on my side most of the time. This bag (Long R-Zip) was plenty roomy for me...with room to spare I might add. The diagonal cut really does help a lot. However, I too noticed being able to see right through the material and to be able to see the down was a little bit concerning, but not much really. The bigger issue to me was when I held the bag up to the light in a window and could see so many places where the goose down was "migrating" in the bag and leaving some spots with zero down...I know we don't sleep holding a bag up to the window and that you can simply fluff the bag out- but I traded this bag for the super stretch model (800 fill) for a little more money. The bag is quilted in such a way that the down stays uniformly even around the bag. The fabric on the U.L. Super Stretch Down Hugger is tougher and thus a hair heavier, but worth the peace of mind to me. The SS model also does actually stretch with you and "hug" your body meaning it will hold warmth more effectively and efficiently. The spiral hugger is definitely a great bag, not disappointing really in any way...but I wouldn't put it at the top of the line mark if that's what you're looking for. Oh, and I did try the bag in the lower 30's- no worries there. Warm as toast...didn't hardly stay in the bag. One more piece of free info for you, I emailed Montbell asking about these two bags specifically and they said that next year's super stretch model would be cut on the diagonal as well. Happy sleeping.

Tested the bag for the first time this past weekend. The specs are very accurate, size, weight, stuff size also. The temps only dropped to the low 30's so im still eager to test it in colder weather, but the DWR treatment was great. Woke up, shook the bag off and it was perfectly dry. I had plenty of room to move around(im 5'9"), and was def toasty(obviously since its rated much lower than the temps were)one thing the pics do not show is the color finish......its a bit darker red, with almost a charcoal kind of fade to it, hard to describe. i will post some pics up soon.

One of the first things I noticed upon receiving my sleeping bag was that the color appeared to be dark in spots. Upon closer examination I realized that the shell material was so thin that you could actually see the fill material inside. I was surprised that the fill material was do dark so I read the attached tag and became aware that the sleeping bag fill contains 90% goose down and 10% goose feathers. I own a Marmot bag and its tag states 100% goose down. I'm not sure if this makes any difference at all, but I think Mont Bell should have been more upfront about their actual fill material.

With that out of the way, the bag is as light as advertised and it definitely provides more room to move around (I am 6'1", 210 lbs). I have not yet tested the bag down to its rating, but it does not appear to be as warm as my old 600 fill Marmot bag. With my Marmot bag I would have to sleep on top in warmer weather so that I wouldn't sweat. However, with the Mont Bell it was sufficient enough to just unzip the bag.

Overall, this appears to be a great sleeping bag:

Pros: Light weight and extra roomy

Concerns: Durability of shell material, comfort in the lower temperature ratings, fill material

Based upon my expectations of a light weight 15 degree down bag I would rate this sleeping bag 4 stars. However, once I factor in the reasonable price and the excellent wiggle room, this bag is tough to beat (provided it proves equal to its 15 degree rating) and thus I rate it 5 stars.