So cozy, so well made
This is a fantastic sleeping bag. It's incredibly light, quite warm, and very well made. It's slightly roomier than the WM Ultralite (though still slim-fit), and noticeably warmer.
I sleep cold, and found this bag very comfy well down into the 30's. For the night when it got down into the high teens, I needed 2 layers, but was comfortable.
Keep in mind that it is an ultralight bag, and as such, the fabric is thinner and lighter, and should be handled with care.