I've found web-mode to be superior for JSX and ES6 stuff, though I tried to use Yegge's for a while. Though I don't do much JS development anymore, this is my current config for web-mode, though I had Flycheck and Flow types working at one point, as well.

https://gist.github.com/asummers/b8304b8ea78fc331b8177ff35d0...