I've been wearing this shoe for about 15 years, first at REI and now at Revain. I always order the same size and so far I have about 4 out of 6 on a shoe that really fits. I have a wide foot with a high instep so 12W should be perfect. However, for unknown reasons, twice I received these shoes marked 12W, which were too small. I first noticed this at REI and had to buy a bigger shoe, but one day I got a too narrow 12W from Revain. In this case, I had to walk barefoot in them for a while before they opened up enough for socks. However, the last pair fitted perfectly the first time I put them on, so I have to assume it's a shoe labeling error (the actual inside of the shoe, not the box). The shoes themselves are great when they fit!