I like ReasonML as a language, and it is really simple to build basic components. Having said that, there are some things in the JSX that I don't like as much:
* You can't just put raw text in the JSX for things that are static - instead you have to include them with React.string or React.int, for example. This clutters up the HTML a bit.
* Adding CSS styles through ReactDOM.Style.make() is quite verbose - I prefer doing styles outside using something like scss.
* Some of the odd things like React.useEffect3() are a little strange. With things like Babel, it seems like there should be a better syntax.
Given things like this, I could see writing a lot of code in ReasonML and then importing it into regular React JSX. This has the unfortunate downside, however, of losing some of the blazing fast development speed you get running the ReasonML dev server.