Good one, mreid.
Baz, fwiw, my wife tried crocs (for recent PF) didn't like them. She's been buying Aveo brand from
The Walking Company. Where they fit, not just the shoe size, but fit the
shoe bed to the bottom contours (of your feet) via a computer and a pressure mat /map.
The take-away here is that the shoe industry will become more and more custom for you needs.