I wanted to use TypeScript with a new React project, but the biggest problem I had (which eventually lead me away from using it) was that typings were so hard to get ahold of. Built something in JS? Sorry, you have to provide what is essentially a source map in order to get it to work with TypeScript. That should be a non-starter for anyone who is doing more than a hello world app. Figure out a way for me to use TS without having to create a bunch of extra type garbage in my app and I'll upgrade my code base immediately.

If you're using a library and can't find bindings then I've found it's worth the time creating them yourself for any reasonably sized project. This is annoying and time consuming up front, but the benefits you get down-stream easily repay this initial investment.