I evaluated and used it briefly for a hobby project before starting my current job. We have a lot of existing jQuery plugins, so it seemed that my options were

I evaluated and used it briefly for a hobby project before starting my current job. We have a lot of existing jQuery plugins, so it seemed that my options were to either add a bunch of new dependencies that duplicate their functionality in React, start a big project to move all jQuery based components over to React, or stick with jQuery (or React wrapping jQuery, which sounds like a number of headaches). In the end I decided to use Riot.js for new components instead, which is tiny and plays well with all of our existing jQuery dependencies so we don't take a huge hit on overall transfer size. I would use React if I were building a new front end from the ground up.