[tomekowal]

I am working full time with Elixir and Phoenix for more than one year now and worked with Erlang before that. It is great to see how well thought out all the abstractions are (both in the language and in the framework). I saw couple of companies cautiously introducing Phoenix in their stack and then going all in. One of such stories will be presented at Erlang User Conference: http://www.erlang-factory.com/euc2016/ben-marx

Comparing to Ruby: Phoenix promises to be as productive as Rails, but more performant and it keeps the promise if all the libraries you need are already ported to Elixir. Even if not, people consider writing them from scratch.

Comparing to Erlang: Elixir fixes a lot of problems like encoding or inconsistencies in standard library. It introduces many new concepts borrowed from Ruby so it might be a little overwhelming for Erlang developers (Erlang is really small and simple language - the hard part is OTP).

Learning Elixir is like learning to touch type. Initially it slows you down, because you have your habits. You need to learn new abstractions, because old solutions just don't work. After short period you are as productive as before. After a month you can deliver hight quality code quicker which is the ultimate goal of every programmer :) And it magically scales on more machines or at least utilizes all of the cores.