I really like it.  I wore it on a 5K run just yesterday and it felt good.  I definitely have to concentrate on my technique because I still tend to lean backwards instead of falling forward.  I use it for CrossFit all the time except the other day when we had to climb rope.  I switched to my other shoes just because I didn't want burn marks on my month-old shoe ... maybe next time.  I'm still getting used to the shape of it.  It's not uncomfortable, just different feeling and my movements aren't limited.  Anyway, if you're thinking about it, give these a try.  Mine were black with the silver N (as opposed to the one in the picture).