Mine just arrived. I went with the tried-and-true black on grey. I went with the sizing tool, and I think they recommended one that's way too big. I wear a size 43 or 44 suit jacket, and AS recommended a size 46. It seems a bit huge compared to what I'm seeing in the above pics. I did state that I would occasionally wear fleece underneath, but not a whole sheep...
Don't worry, you'll probably grow into over the next decade or so it'll probably last you.
