I frequently switch between ElixirLS, Lexical, and Next LS in order to test each out and compare/contrast. I decided to create a brief feature comparison matrix with some of my findings: Elixir Language Server Comparisons · GitHub
I reached out to some authors and devs familiar with each tool in order to be as fair as possible. Each of these tools is a large undertaking and takes tons of time and effort from the maintainers. A simple 2D comparison table can’t tell the whole story, so take it with a grain of salt. I’ll be doing my best to maintain and update the list as tooling evolves and adds/changes functionality. 
