Arc'teryx Atom LT Hoody outperforms on durability and active fit with its Coreloft insulation and articulated design, as noted in Outside magazine reviews. Patagonia Nano Puff Hoody wins on packability and sustainability with PrimaLoft and recycled shells per RunRepeat comparisons. The Atom LT is the stronger choice for mountain use while the Nano Puff suits travel packing.