It all depends on where you live. If you live somewhere where its icy then more camber will give you better edge control will more rocker will have the opposite impact. It does all com down to personal preference though. I ride a very heavily rockered ski in an area know for ice because i like the rocker while my friends can't handle any rocker on the same slope. It also depends what your doing on the park rails, jumps or a combination. But again it still comes down to personal preference not what NS thinks is better
its really depends on how ur riding. charging hard, ice hill, and/or hitting big jumps, Camber all the way. jibbing, soft/ fresh snow, or just having a more buttery/damper style, gota have some rocker for sure.
All of my skis have both. Even my old school Volkl Explosives have "rockered tips" and by that I mean I got them for free because someone bent a tip on one- so I bent the other one to match and ski the shit out of them now and they are even better that way than they were fully cambered.
Think of it this way- camber gives you grip and pop and really positive energy feedback in the turn.
Rocker gives you quicker initiation, easier smearing of a turn and more predictable flotation.
A combination of the two is what you really want, so shop around. Find a shape and core that works for you and go with it. Don't feel like you have to settle for one or the other. See what I'm saying?