Not only comfortable - but really cute too.  Not just a flip flop - Fit Flops hug your foot and keep you more stable.  I've been wearing them for several years, since they were first introduced - and they are by far, the most comfortable sandal I've ever worn.  I can tell when I need a new pair, because once they're worn down, my lower back starts aching - but as soon as I put on a new pair . . . my back is relieved!