Thanks for the feedback everyone.

LL Bean doesn't state loft or fill weight, but I called them, and they were able to come up with a fill weight after keeping me on hold for a few minutes. The LL Bean down seems to be slightly higher quality if their claimed fill power number is accurate--who knows though. The Marmot bag is EN 13537 tested. One reviewer on Bean's site complained about the zipper on another Bean down bag getting stuck on the draft tube all of the time.

Marmot Never Summer:
Weight: 3 lbs, 9 oz
Fill weight: 30 oz
Down fill power: 600+ goose down

LL Bean 0F:
Weight: 3 lbs, 1 oz
Fill weight: 30.35 oz
Down fill power: 650 goose down

Bean also has a -20 F bag for 1 lb/$90 more which is looking like an attractive option too.