Regarding loose- vs. tight-fitting --

It just depends on what you want to do with it. I'm fine with loose because it gives me room for more layers for really cold days (even a sweatshirt if I really want it). My shell fits more snugly in the body, but then again, the thin fabric flaps and buzzes in a good wind, too. The Showers Pass jacket doesn't feel too bulky on my arms, either, and I'll be it's due to how they lay out the seams -- they wrap around the arm instead of going in a straight line.

*add-on* I think the long arms (mentioned by kyakdiver) help to keep my wrists covered, too.

Anyway, just trying to complicate your decision...