Insulation comes in many forms, down, synthetic and merino loft are some of the common terms used. Your standard looking puffer jacket may look all the same to some, but the performance between the quality of insulation in warmth, compression and weatherproofing varies a lot. Key points to think about in choosing the right down, puffer or insulated jacket is, will it get wet, is compressed size important, how easy is it to wash. Down is warmer for it’s weight and compresses more for packing, it also breaths better then synthetics. Synthetic are more durable and can be washed easier. Merino fill is similar to a synthetic fill for weight and durability, but is a nice natural breathable alternative.