We decided to use Flow in a rewrite of an existing React project at work. I found all of the type boilerplate around React/Redux to be somewhat cumbersome at first, but after a few days I didn't even think about it anymore. It feels a little strange writing React code without it at this point.
Same, we're using Flow in for our React Native app but not yet in our older webapp.
I've found more bugs that way that more than offset the extra time spent writing types and being a little bit more verbose to keep flow happy.
The minor annoyances are around the edge cases. Like eslint/flow throws propType errors when using props that were dereferenced from `this.props.someObject`. But you can just write the longer version `this.props.someObject.whatever` and everything's fine.
