I didn't have problems with sizing. I picked the same size as my running shoes and they fit fine. Crocs look how they look so expect women to show their appreciation with laughter and furrowed brows. They are very light and comfortable, but I do find that my stride changed to compensate for lower arch support and heel support. After a long walk, you may find calluses on the balls of your feet, largely due to the need to push off from the toes. I haven't had any trouble with slippage, and they seem very durable after a few months of regular wear.