I went through a period around the late 80's in which I wore Sperry Topsiders sockless as my summer shoe of choice thinking that there was no other airier option for "grown up" men. Around these parts that was pretty much a Grosse Pointe look, and I was concerned less about appearing too casual than being labeled a country club snob. Slipping out for seconds at a time gave such a rush of cooling relief that it became harder and harder to get back in each time. When males starting wearing flips for snappy casual I was in from the start, but very aware as my daughter said at the time that it was a controversial fashion-forward statement. Once I developed the courage to leave the flops at home or in the car and just accept being known as the barefoot guy it became much simpler, no more decisions, just straight forward health and comfort fully aware that the observer's opinions would be as polarized as are the general public's regarding politics, religion, and everything else.