I finally made it up to my local Apple store to ensure medium is the right size for me in the leather loop. I have a 175-178mm wrist and medium was really nice. The large could work, but the end of the strap practically meets the body of the watch itself, which doesn't look good in my opinion, so medium it is for me! Unfortunately they didn't have any in stock, so I'm going to order one online as soon as I make this post.