If you like to be outdoors during the winter months, then you need a jacket to keep you warm in frigid temperatures. The first decision when shopping for a warm layer is: when will you most often wear the jacket? If you are going to wear it between periods of exertion, after you have worked up a sweat, you will need a slightly different design than a jacket to wear around town or for staying warm during periods of sitting and standing.
Puffer jackets insulation is usually down or synthetic, or a hybrid of the two. Down tends to be more expensive, compressible and lighter weight, while synthetic insulation is often cheaper and more water resistant, yet bulkier. Down jackets make for winter jackets that are notably warm for the weight. That is down’s best feature. The negative aspect of a down puffy is that down is vulnerable to moisture and precipitation. When the feathers get wet they clump together and the small spaces between the feathers that hold the heat are closed. However, modern waterproof fabrics and water resistant down treatments can help extend the range in which a down jacket is adequate. The bottom line is: if you choose a down jacket as your winter layer, it will be compressible, warm and lightweight, but not entirely weatherproof.
If you choose a puffer jacket to be your belay jacket while climbing or mountaineering, make sure the hood fits over your helmet and has cinch features to keep out wind and cold. Also evaluate the sleeve cuffs and make sure they are compatible with your glove cuffs, whether you want your gloves to go inside the jacket sleeves or you have gloves with gauntlets that fit over your jacket sleeves.