I bought a pair of these to use when body boarding on a holiday in Cornwall. Following the advice of other reviewers, I got a size 9 (for size 10 feet) and they fitted perfectly. They seemed quite robust and did a good job of protecting my feet when walking from the car park and over pebbles.
The two problems I had with them were that the removable insoles kept bunching up, and the velcro fastening on the right shoe kept coming open. On the last day of the holiday, the fastener came open when I was in the water and the shoe was lost.
When I buy a new pair of aqua shoes, I'll try to get ones that can be tied on with a drawstring or lace.