I've been compilation buffers in Emacs recently and I really appreciate the error and warning counts shown in the modeline.
I've added the equivalent feature to deadgrep: it shows result counts! Really useful when you're doing big refactorings.
I've added some new keybindings to deadgrep.el, so I split the shortcut tables into two categories: https://github.com/Wilfred/deadgrep#keybindings
I've done this purely by intuition. Are there good rules or heuristics for deciding when more hierarchy is needed in information, I wonder?