I've been experiencing some left foot pain and realized that I have some pronation on that side.  I love wearing the Tide flip flops during the summer, so I decided to try these.  I ordered my regular size and found them way too big, so I returned them and ordered a half size smaller and they worked well.  The orthotic insert is a little more severe than I expected, but I quickly got used to it, plus my feet did not hurt at the end of the day.