These are the slides for a recent talk I gave at PDX Node on ClojureScript and why one might consider using a transpiled language.
The long and the short of it is: immutability. I'm convinced that immutable style programming simplifies your code and saves many bugs. Having it baked in to the language makes it much more useful than adding it through a library since most of your other libraries (and habits) wont support your immutable library. In this way a language that is transpiled to another language can actually be different, and I believe better, than the host language.