I have a narrow foot and find the "one width fits all" sizing to be a challenge.  After trying on many Croc styles, I found I tended to walk out of them easily.  With the Cleo II, the movable back strap can be placed high over my arch or at my heel for a more secure fit.  Also, the two straps at the toe give a bit more cling to the fit.  The shoe is great for pool side or casual wear.  Since the shoe is too wide for me and I tend to slide around in it, I would not claim it to be a comfortable shoe, but for short wear around wet conditions, it is a good solution.