I wear a wide size, and I ordered wide. What came was WW and is very comfortable. I probably could have gone down a half or whole size in the WW. my only complaint is the strap across the heel falls down. If the side straps that hold it were a little farther back, I think that would solve it. I have it in the shortest length. Might have to poke another hole to shorten it some more.
Otherwise, I am VERY happy with this shoe - I don't say that about shoes much...