Really like the idea of Flow but doesn't look like IDE support is there yet? This is the killer feature of types in Javascript for me - not sure I'd adopt it until then.
I've been testing atom for front-end development in the last few days and it's pretty good, definitely worth checking out (I'm saying this as a vim-lover)
Atom with eslint, the react plugin and eslint-babel is just amazing for ES6/7 and React development. It's so much faster than it used to be, it's actually amazing.
For sure, tooling is an area that will get better over time. I am quite happy with the very simple vim-flow, but TypeScript's tooling and overall ecosystem (tsd/definitelytyped) is a lot more mature.
I've been testing atom for front-end development in the last few days and it's pretty good, definitely worth checking out (I'm saying this as a vim-lover)