Love these, but they run a size large - normally wear a size 7 - had to return them for a size 6.  Wear them quite often - my feet have a very high arch so the top strap tends to start digging in to the top of my feet after a few hours (but that's an issue with my anatomy, not particularly an issue with the design of the shoes.  Perhaps if the material on these just a more elastic or flexible?) - doesn't stop me from wearing them, though - when that happens I just kick them off for a while under my desk at work and then I'm good to go again!