Regarding the "Flux" frameworks, that's not a problem anymore - basically Redux (which improves on some of Flux's faults) has won. Its developer was hired by Facebook, so I guess it's kind of officially sanctioned now.
I'll be evaluating mobx for my next project, definitely, along with Relay. If I can maintain the same view-as-a-function-of-state approach of redux while writing less code, I'm sold.