In the blog post, I have one example of the React use case with screen capture.

I find it very helpful to have properties defined, so when I use the component, I immediately know what are the props I can provide.

There are some 3rd party React components that won't have type definitions yet, but the popular ones are well covered. I have written most of the components I have used, so I haven't had many problems.

My team uses it at work and love it. Both of them were new to me when I started (was using angular in vanilla JS) and it's been a really nice experience, the type definitions definitely help with learning a new codebase. I'm thinking of introducing typescript to my personal projects at home, but so far I've been too lazy to do the initial setup work.

From a React newbies's perspective, the React community is much more in the es6 camp than Typescript. Many of the starter kits are in es6. It's not a huge deal.

I actually write most of my front-end code these days in Aurelia, which is written in es6, but they actually have type annotations which Babel knows how to deal with. So basically the tooling can auto-generate the *.d.ts files for you.

That said, Typescript natively supports React syntax through TSX files, which is nice.