Dear lord, this turned into a novel.
I have to admit that I'm a down coat junkie. I have two of them currently and I'm drooling over a third that I want to add to my "quiver". Sad, but true. Here's my inputs on what to look for.
Brands:
Lots of good ones out there. Shop around for quality, fit, and the features you want. Mountain Hardwear, Sierra Designs, Mont Bell, North Face, Isis, etc.
Goose down vs Synthetic:
Goose down and water do not get along. Synthetic down keeps its insulative properties when it's wet, which can be extremely useful in winter sports conditions. Goose down just becomes a wet rag with no insulative properties. The trade-off is weight (goose down is lighter), warmth (goose down is warmer as long as it stays dry), compressability (goose down compresses better), and price (synthetic is cheaper). If you're going to be using it in wet conditions (I would include skiing if you're wearing it without a shell), in any conditions where you may be sweating, synthetic may be the way to go.
Fill/weight:
How warm do you need to be? Fill is an important factor. The lighter weight down coats are usually in the 200's to the 300's. The higher the number, the more down is in the coat. Also, the more fill, the bulkier it will be. If you just need a nice warm insulating layer, a lightweight fill is the way to go for bang-for-the-buck. The thin jackets are suprisingly warm when worn with a windproof shell. Also consider a vest if layering to cut down on bulkiness without losing alot of warmth.
Fit:
More companies are making women-specific down coats. Check them out because fit can make a big difference. Just don't sacrifice warmth or quality for cuteness!
Hoods:
Built-in hoods will add a HUGE amount of warmth. Consider this if you'll be using it in extreme cold or as an emergency outer layer.
Here's what I have and what I like/dislike:
A 300 fill North Face down coat (no hood - they call it a "sweater") with single layer baffles that I bought for around $200 six years ago. It's THRASHED and totally packed out but I still love it for camping, backcountry skiing, and other activities where it's likely to get dirty and ripped, since it's old and busted up. The biggest downsides of this coat are it's layerability (it's bulky under a shell), the fact that it's down and not waterproof (I've had some wet days in the backcountry), and no hood.
A Moonstone 700 fill hooded jacket. Similar to Mountain Hardwear's Sub Zero but WARMER. I got this coat for ice climbing and it is heaven. It's goose down, but has a waterproof laminate so the down will never get wet. It is double baffled (so no baffle seams are exposed). It is extremely bulky and hot, so I wouldn't recommend it for anything but standing around in the sub-zero cold.
What I want and drool over:
The Mont Bell ultralight Thermawrap parka. Packs down to the size of a softball, it's synthetic, and has an excellent hood. My buddy used his in Jackson last year when it was 20 below.
