Flux definitely has a following among the community. I'll let someone else talk to you about them.
Personally, I'm gonna suggest the K2 Auto Uprise. They're a good binding that'll do it all. They're stiff enough that you can take them all throughout the mountain, but they're still playful enough to have fun in the park. They're my go to binding whether on my Atomic Radon (stiff plank) or the Sentury Sync I used last year (rockered park board). The Angry Snowboarder Blog Archive 2012 K2 Auto Uprise Used and Reviewed is a review from BurtonAvenger regarding the bindings.