I'm not a technical guys, so bear with me. I got these a little while ago and and waited to give them a good run. I ran 3.7 miles, slow and easy, to give them a chance to break in. About half way through they started to "open up" a bit and gave me a little more bounce. Great fit, they have good traction for light trail running. They are a little stiff, but that is normal for trail shoes and just enough bounce for street running if you just want less cushy street running shoes. To top it off....they look good to boot! Again, I just got these and only a light run on them, so maybe they will open up a little more. Hope this helps!