I ride clipless with a mountain bike shoe.
Contemplating the coming summer, I think I might like to try riding in sandals for the coolness and because I hear people report easy walking in bike sandals (Lake or Shimano).
However, I did a search of this forum and I could not find an instance of a fixie rider wearing sandals.
Some of this could have to do with the fixie culture, but it could also have to do with the greater demands put on shoes by riding a fixie.
I mean, I blast up hills because I can really pull on my pedals; and, could I do that with sandals?
Anyway, if I don't hear of a fixie rider successfully wearing sandals I'll probably save the money.