I have bought this type of shoe before, but not from keen. I am female with a low arch and borderline wide foot, and the women's styles sometimes don't fit. This fit perfectly, and it is pretty unisex, style-wise. I went one size down from my women's size, W11 to M10. I'm very happy with these, the estate blue is a beautiful color, a bit brighter then navy.
***Edit- I have had these for several monthes and still love them. If they were more feminine, I would wear them all the time. This week I took them to the Poconos, and was very happy with how they felt while creek walking. I felt stable and my feet didn't tire out like they have in the past. I will ALWAYS bring these with me for that, from now on, so mush better then other water shoes I have worn. Keep in mind though, from soaking wet to dry takes at least 24 hours, longer if you don't have sun.