I was hesitant to buy these with the lack of reviews, but I'm glad I did.  They are super comfortable.  The sole is very flexible but provides enough protection for the foot.  I like the way the material hugs the middle of my foot, no sliding around.  The feel of the material around the toe area did take a little getting used to, but now I don't notice it.  Plus, I get lots of comments on how cool they look.  And made of recycled materials!  A win all around.