Git is now my "ctrl-s" in my editor. The autosave is set to 500ms. I never waste keystrokes saving now. maybe not as fine-grained as this article suggests, but whenever 'jumping' from rock to rock while climbing" as the starting metaphor shows, it is an awesome alternative to traditional 'saving' on the filesystem.
FYI if you're treating git as a durable place to save your code you might want to set 'core.fsyncObjectFiles = true'.
I've personally had my git repository become unusable when my laptop lost power too soon after making some commits, before the background periodic sync occurred. (XFS)
We have enough cheap space that we should be able to easily have (non-binary) file changes have a history log in our file system itself and be able to revert local changes without needing the full change graph that git entails.
I'm all for small commits, but committing every time ctrl+s happens would be an anti-pattern because ctrl+s doesn't imply it compiles whereas I'd want any commit to compile. (passing tests optional).