Looking for some advice on a new bag. The three that I am currently looking at is the REI Igneo, Kelty Ignite, and the Kelty Cosmic. I am looking for a bag to do an AT through hike in 2016. As well as I have a trip coming up in a little more than a week in the Smokeys hitting the Ice Water and Peck's Corner shelters. I am hoping to take advantage of REI's 20% off sale going on to get one. The REI is definitely on the higher end of my price range but it also seems to be the best weight for warmth ratio, however, I do like the more girth in the Kelty's. Any thoughts on the bags would be much appreciated.