Best overall
For camping treks, and for lodge beds that are a plank
Therm-a-Rest NeoAir XLite NXT
R-value 4.5, ~350 g, packs to a water bottle
The warmth-to-weight benchmark and it makes a hard lodge bed sleepable — it is audibly crinkly, and in a shared dormitory that is a genuine social cost.
R-value 4.5 is real four-season insulation at 350 g
Packs smaller than a Nalgene
Turns a plank bed into a bed
Crinkles loudly every time you move
Punctures — carry the patch kit
Expensive
Not for you if: Teahouse trekkers happy with a lodge mattress. Most are, and this is 350 g and a lot of money to fix a problem you may not have.
Check price on Amazon