I rode K2 soft boot step-in's (clicker) system for two years, and while I loved the convenience, I never had the right combination of forward lean, no heel lift, and movement fore and aft available in the binding that a good highback binding system has. You can really crank down the straps on a good high back binding, and the high back on good bindings is incredibly stiff, and flat, so you still have fore/aft movement but plenty of response on heel edge. The Clicker system couldn't be tightened down enough to lock my heel down. The highback built into the boot wasn't as nice, as it didn't allow the movement that I like. I eventually switched back to Burton highback bindings, and started loving snowboarding again.
On hardboots, having been through failures with Burton and Rattrap bindings, once I found the Catek standard line, I've never found a need to try anything else. The newer hardboot step in systems do look very tasty though. Maybe one day, if I can demo a system, I might try it. I certainly wouldn't have the same complaints as the soft boot systems.