My husband recently bought a pair and loves them! He says they make his ankles feel stronger. He also thinks it feels more natural to wear them. Of course, it takes a little getting used to before you can slip your toes into teh correct spots without double-checking!
I tried them out and like them, but I found them a little constricting. I love being barefoot or wearing flip flops, but can't do that when I run. I've personally found that at my current weight, running without decent shoes has been really unpleasant. I might try them myself at some point soon and will let you know what I think. However, my husband loves his and recommends them to everyone!