Not the only advantage...
The NX2's are THREE HUNDRED DOLLARS.
The Gnu bindings knock off $50-$125 off that depending on what model you pick - all Gnu bindings have that auto-release feature on the front strap.
For THREE HUNDRED bucks (I can't stress that enough - and I'm a successful adult), I'll buy a set of Flux RK30's (which even those were under $200) and let the technology mature some more.
I agree it looks like Flow has come a very long way since the disappointing riding experience I had on a set last year (which were a several-year-old model on a friend's board I took a spin on), but I'll let other people pay $300 to trial this new tech, I'll wait for their verdict. And realistically, it'd probably take a demo day at a local resort, to give me confidence in Flow again. I'd have to be sure my experience wasn't like the ones I rode last year - this auto-raising strap might just resolve some of that riding experience, as that allows for a tight strap that Flows haven't been able to do previously (at least ones without ratchets - like I rode).
I'm intrigued, but $300 is not curiosity-money.