I'm trying an REI Magma bag this year with a Therm-A-Rest Neo-Air. Used a 15deg Kelty for many years which worked but required extra layers when temps were in the teens. I've used, and been happy with, the Exped downmat 7pad. It's a bit bulkier and heavier though and thus the reason I'm trying the NeoAir. I also have a Z-Pad or a Roll of foam that I may, or may not, include. Tanner is right that weigh is not an issue, but space may be. Need to see if I have space available. Probably will on shorter hunt, not sure about longer where I have a lot more food. If moisture is a real possibility I agree that synthetic would be the way to go on the bag.
