Clojurescript a lot of its success to the use of the Google Closure compiler, which really shines when you transpile because you can ensure that the resulting js is suitable for the Closure compiler.
Also, we seem to run into correctness bugs more often that we would like. I guess we are really stressing it.
It wraps the TypeScript Compiler and outputs CC compatible type annotation comments.
- It's a hack on top of TypeScript compiler
- It gets broken by TypeScript upgrades and is usually several weeks behind TS version upgrades.
I'd be really wary using it in production
- Pretty much everything you use (e.g. Angular or React or Babel or Webpack or equivalents in other languages) is being built by a handful of people
- It interacts with TypeScript in a way that tends to be more sensitive to changes, but being some weeks behind the latest release of a compiler is not the end of the world, and we do continuously upgrade
I agree you should be wary of using it in production though because it's not really user-friendly yet. Though if you can figure it out it does work and some people are successfully shipping some apps.
I can't justify bringing it in in our current setup though :(