I am disappointed with these shoes.  The mesh is so weak that after only two months there is a hole in the mesh of one shoe and another forming on the other shoe.  Whether the sizing is different from any other shoe I've purchased, it is the smallest 6.5 I've ever had.  They have only been worn at the gym three times a week and on walks around the neighborhood.  I have always loved the brand and cannot imagine what went wrong. If you buy a pair be sure and go at least one size up. I purchased these from one of Amazon's dealers (Shoe Station).