I recently "saw the light" with a "quilt" for the second (northern) half of the AT. All the talk on here got me interested, so I checked it out. what I wound up with is a kind of a "hybrid" quilt, which has a closed foot box but an open back, but which has a system to attach the quilt to your air mattress, allowing us tosser/turners/side sleepers to stay warm. What I wound up with is a Katabatic Gear "sleeping bag", reviewed here for the 30 degree "palisade" model, called their editor's choice for best Ultralight "sleeping bag":
http://www.outdoorgearlab.com/Ultral...ar-Palisade-30
I bought the slightly warmer 22 degree version, the alsek, same bag, just a tad puffier, 3.5 ounces heavier (21 oz vs 17.5 for the palisade). The company is based in Lakewood CO, about 10 minutes from my house, so I was able to do a hands on check out of the bag and chat extensively with the owners, a cool, experienced long distance hiking young couple. These puppies are not cheap, but I really like my Alsek, and have used it down to the mid 20's in comfort, plus in the 60's (nighttime temps) also in comfort, just loosely draped, as already mentioned one big advantage of this "quilt".
(I keep using quotes around "quilt" and "sleeping bag" because this is a kind of a hybrid bag/quilt).
These are actually on sale right now for a couple more days, 10% off.