The bottom jacket is the hottest that you can. If you are spending winter in northern viskensin as I did while testing them, it is not a bad idea. But if you are just looking for a little extra warm during the trips to the shoulder season, or even backpacking in high altitude summer, then you do not need 800 feeding power, a large scale winter parka overstaves Has been done
We suggest that you have to stick to the jacket A down phil power rating There is no reason to spend on the jacket with at least 500 for mild use, but until you are going under the cold temps (or you are one ForefrontIf you spend your time mainly in low climate, get a light jacket.
Also remember, in terms of backpacking, you want to keep in mind how packed the jacket and how much weight it adds to your pack. Unfortunately, the lightest jackets are high filling power, as you can trap more heat with less bottom, but again, be realistic about the temperature you have and you can get away with a cheap jacket Are.