I have a Rab down jacket that is very light and comfortable to wear and effective at keeping me warm. Onthe other hand it's not great fo wanking in as the down compresses to almost nothing so it fells like wanking in a sheet of nylon.
My parkas on the other hand have polyfill which is far more resilient so when wanking in them there's a good thickness of padding which makes them feel so much better than down.
I also have a few very old parkas that have the original wool padding that was use before polyfill. They are very heavy and quite stiff so nowhere near as horny.