Backpacking ... NeoAir. If you don't mind another half pound to pound, a folding Z mat. Protects the NeoAir from puncture, adds warmth underneath, and I think it about triples the comfort despite only 3/4ths inch of thickness. Well worthwhile if you're not going truly UL.
Something often overlooked is the affect of rocks and sticks on an air mattress. Even if a rock doesn't puncture it, it can put enough pressure on a seam to weaken it. A pad underneath can keep your mattress alive longer in addition to holding the heat.
