We have designed Flow so developers can reap its benefits without losing the “feel” of coding in JavaScript. Flow adds minimal compile-time overhead, as it does all its work proactively in the background. And Flow does not force you to change how you code — it performs sophisticated program analysis to work with the idioms you already know and love.
Mi se pare mai interesant decat alte chestii similare (gen TypeScript etc) pentru ca nu te obliga sa adaugi type annotations. Din ce vad poate sa isi dea seama automat de tipul datelor in multe situatii.
Ce nu imi place insa este faptul ca trebuie specificat acel comentariu /* @flow */. Asta intr-adevar e o chestie minora, insa se putea face treaba mai elegant cu jsdoc.
Oricum, realist vorbind nu cred ca o sa ma folosesc de tool-ul asta vreodata. Prefer sa fac astfel de verificari in interiorul functiilor prin validari.