Can't help you with the Flux. But I do own 2 pair of Autos; the Uprise (2009) and the EverS(2010). Can't honestly say the Evers are worth the extra ching unless you can find a really good deal. The first year I heard they had trouble with the Auto cable system, but I've never had an issue. The K2's are super easy to set-up, ultra lite, and the one buckle thing is really nice if you're in a hurry or are just lazy. I'm lazy. For me, not a pressure point anywhere, which actually was scary first time on as I wasn't sure if they were gonna work. I've ridden them on a RIDE TWS, a Rossi One Mag,an Angus, and a Jones Mountain Twin. For refernce, I've owned Neideckers, Unions, Burtons, Flows, and Ride binders. And....... I'm an all mountain freerider, spend absolutely no time in the park, and only hit an occasional jump or feature. Good luck.
"I didn't do it, and you can't prove it."