Gripes I've had with symmetrical/near symmetrical skis in pow is that the tail generally floats as well as the tip, and this puts you backseat at lower speeds, and even at higher speeds, makes it easy to catch a bump wrong and tip dive. I feel like full rocker solves this problem, as the tail isn't pressing down into the snow and supporting the tail end, if anything the snow ends up pushing it down.. This makes it possible to ski with a much more forward/balanced stance in deep snow. Landing with a fully rockered ski I feel gives you less margin for error than with a traditional straight tail (landing backseat will make you wheelie with a rockered tail)
