Down jacket fit

Should fit close to the body if not layering much under it. Fit should be close enough but not compress the down with full range of motion in the arms shoulders and chest. I find the GW to fit weird. Tight in the chest and shoulders, loose in the belly, and long in the arms. Might just be my body type though.

For reference I have, and love, a Montbell UL Down Parka, 2.5oz down.

IMO a lightweight puffy, like the Ghost Whisperer, is a layering piece best used in a system of (base) layers culminating with a wind and/or waterproof shell. As such, I like it to be fairly close fitting…it is the final insulation layer and any extra space (air) is just space for my body to heat up unnecessarily.

I suggest you test fit the jacket with the max expected layers underneath and attempt to eliminate any unnecessary "slop" in the fit.

I'd try as many different brands as you can IRL to see which fits you best.

I thought I wanted a Patagonia puffy, but I don't. Need to try more, including the GW. Fit is important and personal — and all the more so for female top layers.

If it's tough to put on a down jacket that is close-fitting, it'll be hard to get it on when you're in a sleeping bag, an emergency bivy, a seat on a ski lift, etc.

Skip the hassle and get one that is just slightly roomy, so you can wear a fleece underneath or get it on over your other layers in a pinch. No need to struggle into a skintight down suit.

Maybe others have an A-B-C-D layering system that they never deviate from. For me, I might toss an insulating layer on over or under, depending on conditions and how quickly I expect to take it off, or how quickly I want to warm up.

I like mine close, but not tight, to the body.
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That way I can add a light fleece underneath and/or a windshirt over if needed.

The Montbell UL Parka is my preference.

Most important, it needs to be long enough to cover your waistband when sitting or bending over, with any hiking pants or shorts you might use!
Second the sleeves need to be long enough to easily cover your wrists, longer is better, even when reaching.
After that wear all the layers you might ever wear underneath:
BaselAyer, thin fleece and windshirt might be reasonable at some point.
It should go on easy over that. Make sure armholes are roomy, as the last thing you want is to have to wrestle into it like a contortionist at night inside a sleeping bag.
After that, the trimmer the warmer, but it's really not a big deal, as long as the wrist, neck and waist are snug with elastic.