With one install command, you get a polished Vim/Haskell setup with tab completion, type inspection, Hoogle, hinting, unicode symbols, etc.
Also has a nice dark theme. In fact, I use it as my go-to Vim configuration on new systems, even outside of Haskell.
It also lets you pipe code to the Haskell REPL for live evaluation (via tmux).
EDIT: Add video