Probably right now. But that's a good question. As you've already seen, the documentation on http://coffeescript.org is phenomenal.
As a dev with maybe 1.5 years of JS experience, I've learned coffeescript in a week. I still don't have the coding style that my code reviewers want, but I'm writing functional code.
The biggest hurdle I've found is getting an auto-compiler for coffeescript. You don't want to do it manually:
I have not had great luck mixing coffee --watch and gvfs for either FTP or WebDAV. An ugly, but effective solution is to configure your editor to compile on save. The most annoying part of that is when you switch to a project with a different build process, and you have to either reconfigure your editor, or deal with extraneous .js files being output.
As a dev with maybe 1.5 years of JS experience, I've learned coffeescript in a week. I still don't have the coding style that my code reviewers want, but I'm writing functional code.
The biggest hurdle I've found is getting an auto-compiler for coffeescript. You don't want to do it manually:
everytime you want to recompile your code. But there are tools for that! https://github.com/gruntjs/grunt-contrib-coffee