It's not the boilerplate that get's me. It's just easier to reason about the state using Redux (imho). The idea of 1 single global state which mutates and pushes down (instead of managing observables all over), makes it easier to see when/where something changes. The idea isn't new (check react-cursor for example).

That said, there's nothing wrong with vanilla flux. Just that I find redux much easier to understand and follow.

I haven't really found redux to be all that unstable, though.

Redux is literally ~100 lines of code (you can check out Dan Abramov's Egghead.io series about it in which he basically rebuilds Redux).

I'm among the many people who previously used vanilla flux and prefer what the Redux style brings to it.