I originally ordered the Preston in M11. When I got them they were too small. I went to the Crocs Waikele outlet, Ala Moana Shopping Center store and finally the Waikiki Store. There, the only golf shoes that would fit were the Preston in size 13. It's true! If you are between sizes, go up 1 1/2 sizes. So my original 11s turned into comfortable 13s in a different style shoe. If there are Honolulu shoppers I suggest you go to Waikiki if you want the widest selection of golf shoes. For those of you with more "modest" shoe sizes, the Ala Moana store will have most mid-sizes.
Oh, and the Waikiki staff was soooooo helpful, too!