First, I do really love this jacket and am happy with the purchase. It's extremely lightweight and packs down to nothing. I use it in the cooler winters of SC (keeps the wind out on the beach) and also as a midlayer when skiing out west.
I bought the aristocrat (dark blue) color and don't have issues seeing the feathers through like some others have mentioned of the lighter colors.
I have broad shoulders and it does fit a little snug under the arms, but never has restricted any movement. I usually wear a small, but did get a medium for layering purposes.
The only other issue I've noticed is that it snags easy, especially when the pocket zippers are open. The sleeve will snag on the pocket zipper. I just try to leave the pockets zipped closed.
Other than that, great jacket!