Elixir is not Ruby, it just has a somewhat Ruby-like syntax. The similarities end there. Elixir does not have the performance issues that Ruby has (although it may have different ones!)
Got that. My point was that you are choosing between a language that looks like Ruby and a language that looks like Lisp. That's a big difference and many people, I would assert, would choose one or the other without hesitation. For me, that would be Ruby.