I use flip-flops mainly before and after showers, but also take them to tropical locales for use in clean areas such as aboard cruise ships.  Because I have heel pain, I bought these to replace a pair that accidentally got left behind at an overseas hotel.  The soles on those old flip-flips were perfectly flat and were uncomfortable because of my heel problems.  The Orthaheel flip-flops, in contrast, have a molded concave, orthotic sole which spreads the heel weight across a wider area including the sides of the heel.  These are very comfortable to wear, with little or no heel pain so far.  I've only had these for a week, so I've not had a chance to use them on a trip, but so far they are great!.

My only issue is that $60 seems a bit pricey for a pair of flip-flops, but then there aren't very many flip-flops offered with orthotic soles, so the manufacturer can charge what the traffic will bear.

I may post an update after my next trip when I've used the Orthaheel flip-flops more extensively.