Great that he pointed out the problems that CoffeeScript solves from JS, it makes you understand better raw JS when you read it.

Welp, that convinced me.

#5) Groovy does even better than comprehensions

ages = peopleList.ages

Yes, that's it! (the list has no property called ages, so it checks each of it's members for that propery and returns it as a list to ages). GPath, baby! :)

I like several things about CoffeeScript. Enough that I actually tried to use it, full time, in a new project I started. After a few days I stopped though and went back to JavaScript.

Why?

Ambiguity. CoffeeScript code can very easily introduce and suffer heavily from ambiguous code.

Some of it can be avoided by becoming a better CoffeeScript programmer I'm sure.
But some of it is a consequence of the design of the language and makes it unsuable to me.