I purchased these for my brother who was accompanying me on a trip to Mexico.  The excursions we were going on said "no flip flops, but water shoes and sandals are appropriate".  These fit the bill of water friendly AND sandal.  He said they are quite comfortable and he is very pleased with them.  He's rather picky so that says a lot.
We went with the dark gray as it's neutral and can be worn with many colors.  I've never purchased a pair of Teva's that weren't worth their money!