I think about it like this.... My line down the hill is a groove, and it's my job to keep my body weight balanced over the groove. Cambered boards naturally lend themselves to a tight groove, and my body is forced to make adjustments that keep my balance centered over this groove. Rockered boards naturally allow a looser groove, and my body is forced to make adjustments that keep the groove tighter.
In a situation where I'm hitting something off balance and/or making a sloppy landing, the rockered board is a double edged sword that 1) can make the takeoff a little sloppier if I'm not managing a tight groove on my own, 2) can allow a sloppier landing to end well because I don't have to work as hard to keep my body balanced over the naturally tight groove of a cambered board.
On the other hand, a cambered board will 1) punish me for a sloppy takeoff if I can't keep my body aligned to the tighter groove...but keeping the groove tight happens more naturally and 2) punish me for a sloppy landing with edge catch.
A couple of other differences:
- my rockered board doesn't treat me very nice if my weight is too far back on the tail during the landing. in the same situation, my cambered board forces the nose of my board to the ground and saves me sometimes..sort of like an ollie in reverse.
- float in pow? nah, not really. my boards are both medium-stiff, and I don't notice this at all. maybe if you had a couple of limp noodle boards, I can imagine a cambered limp noodle board would want to flex in the center and nose-dive into the pow....while a rockered noodle might maintain float.
- Carving is so much more fluid and effortless with camber. That's not to say I can't carve a fluid line with my rockered board if I focus, but it definitely washes out sometimes when I'd rather be zagging.
All that to say, it's really just preference. I like the feeling of both styles. On my rockered board, I really enjoy hard-charging nasty terrain like rough/mogully/chundered pow....whereas my cambered board sometimes makes me feel like I'm about to faceplant if i get too loose. On my cambered board, there's no rockered equivalent to carving a perfect arc across pristine pow or corduroy. I dream of the day I get to try hybrid camber board and leave the traditions behind...but I really doubt I'll stop liking both until maybe I'm a better snowboarder than I'm ever likely to become.
edit: what a bunch of nonsense, lol