well to be honest i got pretty confused when you said rocker and thought you were talking about the evo but the arbor has something in their sidecut for added grip as well.
the never summer evo has what they call vario power grip, where the radius of the side cut changes from being deeper towards the tip and tail, a little more shallow going towards the feet and completely straight in the middle.
the arbor has a normal side cut for the most part except for right under both bindings there a bump the is suppose to grip the snow better
Ohhhh. Well I've only heard good things about the Evo so I'm definitely checking it out.