These are cute, and the right shoe was comfortable. The left shoe, however, was flopping off of my foot. I saw that the left shoe was visibly longer than the right. It was not an optical illusion - a tape measure showed a 1/2-cm difference. That is a half size difference in the US sizing system. You cannot make that work at all in this style of shoe. I have lucked out so far with my other purchases, but now I can echo others' complaints about VFF quality control issues. P.S. I normally wear a 42 in VFF, and ordered a 43 in these as recommended. This would be the correct recommendation if the right shoe is the one that was properly sized.