In reply to bpmclimb:
I got a last-season's Cloudveil down jacket for £50. Excellent value for money.
So far I have only used it round town and such, where it has been excellent - toasty and warm waiting for trains.
In Scottish winter mountains, I always wear synthetic insulation. I have a couple of Primaloft jackets which are great - warm, light, they don't collapse when they get damp and they dry out quickly if they get soggy. They have also proved great at just over 4,500m in Andes and Himalayas. I was planning to go higher, but stuff happened, as stuff is wont to do, and we had to back off sharpish, so I never got to try out my toasty primaloft trousers. I reckon my MH Compressor trousers and jacket would have kept me superbly warm up to a fairly high height indeed, and one day I hope to check this out.
But not for the next few weeks.