Mapping caps lock to escape is nice, but IMO the really useful move is to map caps lock to BOTH escape and control. I use it (via Karabiner Elements on OS X),

Mapping caps lock to escape is nice, but IMO the really useful move is to map caps lock to BOTH escape and control. I use it (via Karabiner Elements on OS X), and it's great: Caps lock pressed AND released in isolation within 250ms is escape. Caps lock pressed in conjunction with another key is control. The way it seems to do it is to trigger key events on key_up rather than key_down, meaning "escape" is triggered when you release caps lock, not when you press it. This can feel a little strange in some edge cases, but in normal usage, I don't notice it at all. This has essentially saved my MacBook Pro touchbar as a dev machine, since I absolutely loathe the touchbar escape key, but didn't want to lose caps lock as control.