I'm seeing a few places this will come in handy:

* toggling booleans in a config file.

* switching a string literal between 'single quotes', "double quotes #{so I can add interpolation}", and :symbols. I do this pretty often. The former is easy enough with surround.vim (cs'"), but the latter is a pain (ds'bi:<ESC>)

* the ability to add a "tap" and remove it with a single key combo is interesting for debugging.