Polaremil - Ooo, the Willow flats are pretty. You know me, a flats girl! I'd love the silver ones. They look like they have a rubber sole. Guaranteed to feel comfortable. My experience with the flats is to order true to size. But sometimes the Choo shoes are all over the map. Do you have any other Choo flats? How about the Yeva boots? I sized 1/2 size up to 39 in the Yeva. I also have the Yang and sized 1/2 up to 39, but could have stayed at 38.5. I have the Walt flats and wear a 38.5. Hope this helps!