i researched these shoes and couldn't find any info or unbiased reviews from athletes which leads me to think they are a fad shoe. however, i liked them very much, they are very comfortable, lightweight, flexible and cool looking. there are some notes on how this design works, something about energy coming from the propulsion and the sole 'waves'. i ran in them and wasn't impressed at all, the shoe feels wobbly when running, the lateral support is very weak, forget trail running or running on uneven surfaces. probably an excellent gym shoe or just wearing for daily use. they are very comfy when walking, i could feel the energy from the heel bouncing my forefoot up, bonus for how they felt when walking around but i was looking for running shoes and these didn't work.  they seem to run a 1/2 large too, i wear an 8 in most every shoe and the 8.5 fit perfectly.