Very comfortable shoes but the heel seems to slide up and down no matter what I do. I put my foot all the way back and make sure the velcro is tight, but when I walk there's some movement in the heel up and down.  Could just be my feet, but my NNew Balance Men's MW577 Hook and Loop Walking Shoe  don't do it.  Also, the shoes squeak and I'm not talking about the soles on the floor.. they squeak internally.