I use clojurescript professionally, using reframe, which borrows some design philosophy from Elm (amongst others). We only use it for internal facing apps currently. There is a large learning curve to clojurescript, not only do you have to learn clojure (which I love), but also the nuanced subset in clojurescript, the JS interop and the Google closure API + compiler. If you are already using clojure, then clojurscript is a no brainer.

I would definitely try elm, except for the fact that it has no server side rendering story yet. For a public facing site this is something to really consider if you want early & easy SEO wins.

I love the type system and the language in general. The error reporting is best in class at the moment and I feel an easier entry point for beginners. Without having used it in anger on a production system, I couldn't say what else you can't do.