Really liked: the simplicity of Go's build, not having to spawn N processes on the server side, the compiler catching so many issues, the very strict formatting rules, all a major win over Python. However, didn't like how verbose the code turned out, especially for parsing or any data manipulation tasks. For server-side debugging/tools, it's also a bit of a build-your-own adventure.
Elixir I found to be much more pleasant to write and subsequently read, more well-suited for back-end tasks, great for generating and parsing data. Also, more things in the toolset for back-end deployment, in large part due to the OTP stack.
Perhaps Go's ideal use case is local system tools, compilers, or anything else that requires concurrency (let's say, creating tools like "ls," or Apache bench, or gcc, or cURL), and something like Elixir is more ideal for building actual servers.