When comparing ElixirScript vs Crystal, the Slant community recommends Crystal for most people. In the question“What is the best programming language to learn for backend developers?” Crystal is ranked 23rd while ElixirScript is ranked 25th.
Specs
Ranked in these QuestionsQuestion Ranking
Pros

Pro Clear syntax
Uncluttered, yet unambiguous syntax

Pro Excellent community
The Elixir community has proved to be welcoming and very supportive.
Pro Great for concurrency
Leverages the existing Erlang BEAM VM
Pro More familiar syntax
All of the benefits of Erlang; without as steep a learning curve of prolog based syntax. Elixir is heavily inspired by Ruby's syntax which many people love.
Pro Great documentation
Elixir's documentation is very good. It covers everything and always helps solving any problem you may have. It's also always available from the terminal.
Pro Elegant syntax as Ruby
Pro Fast performance
Pro Has co-routine
Pro Compiles to native binary
Cons
Con Aruguably no better than a meme language
The elitest attitudes in the community are unwarrented. Not recommendable for production use. Poor error messages, odd compiler errors, poorly documented behavior, etc..
Con Small community
In regards to its age and already past 1.0, the community is still too small.
Con Not cross-platform
No official Windows support.
Con A language only Ruby fans can love
Ruby-ish language.
Con Slow compilation
Con No parallelism (yet)
Not actual anymore.
