Here's my .02 cents on this. I bought a 20* HG burrow with the snaps. I love it. Here's why. While being my lightest sleeping bag/quilt it is also my only quilt. I used it from February till now. All through the spring summer and fall. Even in the coldest temps that I had it in, around Mid 20's, my feet never got cold enough for to wish I had it sewn. However in the summer I could unsnap it or open the bottom to vent. Now for my winter one I will be getting a sewn zero degree from HG as well.
Husband, Father, and Friend.
Scout Master and Cub Master for Troop/Pack 705 of