I wear a 5.5, so ordered these in a 6. They're a little longer than they need to be, but just fine.

Like other reviewers, I bought them for the arch support, which is very nice. I have relatively high arches, and my feet get really sore after a day in most flip flops (or bare). They don't get sore at all in these, both because of the arch support and the rather cushioning foot bed. I'd be happy to walk quite a distance in them.

The other major plus with these is that the straps don't give me blisters or cut my feet, as *many* flip flops (Old Navy, Gap) do. This is both because the strap is wide enough, and because of the jersey lining on the bottom of the strap. Sometimes the edge of the strap, where there's a seam, rubs a little bit -- the only reason these aren't 5-stars -- and it is a little uncomfortable, but again, since it's not enough to cause a blister, it doesn't stop me from wearing them.

The only other thing, which is a style thing not obvious from the picture, is that these are definitely on the casual end of flip flops. They're a little classier than plastic, but the straps are synthetic and look synthetic. I have yet to find a "dress" flip flop that's nearly this comfortable, but if you like to push the edges of where you can wear flip flops, this probably isn't the shoe to do it in.

Otherwise, it's a nearly perfect sandal.