10 degrees is pretty darn chilly for a light coat. At some point you must be trapping your own body heat enough to create warmth or reflecting it back like a space blanket. Only so many ways to do it.
I've got a lightweight patagonia jacket I really like as a mid layer because it does the things you ask. It is more than a lightly insualted shirt, but less than a jacket. But to 10 by itself, not a chance. I also like the thin, insulated jackets instead of one bulky one. I've been experimenting with the patagonia (nice shell, thin microfleece lining) under an eddie bauer jacket that has a thin layer of modern synthetic insualation (can't remember which one) that works great for the warmth bulk ratio and then a simple waterproof, breathable shell. Works great. I've only seen 25 degrees with this combo. Gets too hot with minimal activity.
I think Patrick at Kifaru has the right idea for the kind of jacket you are describing with the insulation he is using. Not aware of anything else. But I am not a guy who would spend $300 on a jacket either.
Hope someone has some great suggestions.
Last edited by 338WIN; 01/13/12.
