Nailed it on the cinch draw location, a small thing that 2 of 3 of my quilts have. Being in the center you always can find it but hanging around my face it can drive me nuts sometimes.
I have the 0-degree version and it is a good quality product. I still haven't pushed it below the mid-20s so I don't know how well it works as it approaches the limit rating. The only problem I've noticed is cold air can get in from underneath, even with two pad straps.
Its a slightly different style from the topquilt in this video, but check out their Aerie sleeping bag/underquilt. I know it unzips all the way around.
Good question! There are a lot of videos that go into more detail about this, but in short, the down underneath you in a sleeping bag gets compressed and provides almost no insulation. Quilts save weight by cutting out that section. I also find that I sleep better in a quilt because they are less restrictive than sleeping bags.
