Just a followup on the NeoAir (if you've seen my recent post on it, just skip this):

While I've seen posts from those who claim to have been comfortable in the NeoAir at 15*F with only a 1/8" closed cell foam pad as supplement, I don't recommend it. The NeoAir is rated at 32* and (after experience) I wouldn't use it below that temperature without a really thick (3/8" or 1/2") closed cell foam pad. (That of course negates the weight savings.) On the other hand, I've taken my POE insulated air pad down to 20* without supplement and to a few degrees below that with a 1/8" torso length CCF pad (I haven't had it lower than about 16*).

We all have different sleep styles and our bodies' "thermostats" are all different. I strongly recommend several nights on the floor at home and at least two below-freezing nights in the back yard with any new pad before you decide to keep it. At least test it at cold temperatures before going out on a 2-night backpack in shoulder season!

I was willing to accept less comfort with the NeoAir for the 8-oz. weight savings over my POE pad. In hindsight, this was a lousy decision!

EDIT: My 3/4 length POE pad weighs 17 oz. The pad it replaced, a 2" thick Thermarest LE, also 3/4 length, weighed almost 2 lbs. The Thermarest was colder, too. It finally got too thin (translated, my hip joints got more sensitive).