The invention of rocker kind of made it possible to get pros of both stiff and flexy/buttery park skis. The only thing you sacrifice is effective edge on hardpack. I'd recommend a rockered ski unless you specifically ride rails or jumps only. That's just me though, everyone has their own style.
Everyone says this !!! But I love stiff skis on rails, IMO even the stiff ski can be poppy and buttery on rails! Again IMO i think it's personal preference. A great person once said,,, what you eat don't make me shit! But opinions are like assholes,, everyones got one!