I haven't used whatever they've shipped in terms of type system, it's possible that that would be a positive differentiator for Elixir now.

With regards to `mix`, you can use literally only that if you like it and just set up `erlc_paths = ["erl_src"]` and write your actual stuff in Erlang in that path.

It's also fine to just use `rebar3`, to be honest; `mix` as a tool is not such a large difference that it should make you more interested in Elixir, IMO.