It seems nobody has mentioned my hack of choice yet: map tab to escape, and shift-tab to tab. I rarely indent manually anyway, and tab cycles indentation levels

It seems nobody has mentioned my hack of choice yet: map tab to escape, and shift-tab to tab. I rarely indent manually anyway, and tab cycles indentation levels in all language modes I work with, so I don't need anything mapped for shift-tab. I do really like the idea of tapping vs. holding caps lock mentioned in another comment here, though. I could probably get used to that instead.