I actually did some experiments with Elixir, and my conclusion from benchmarking them was that Elixir is in fact significatively faster and consumed less memory

I actually did some experiments with Elixir, and my conclusion from benchmarking them was that Elixir is in fact significatively faster and consumed less memory than Node. In any case, Elixir is a great language, and even if BEAM was slower than Node I would still suggest to choose Elixir (+Phoenix) over JavaScript.