I didn't care about Git auto-completion for a long time: the commands are short enough, and I created even shorter aliases for many of them.
But there are things you can't create aliases for, such as remote names and branch names, for example in these commands:
git fetch that-other-guy
git log that-other-guy/some-freakin-awesome-feature
git merge that-other-guy/some-freakin-awesome-feature
When collaborating with others, I like to use the same name for the remote of the other guy as his username on GitHub. Which can be long. In the past I used to be so lazy, if I had to do many operations on his remote, I would temporarily rename it to x
to make it easier.
Similarly, feature branches are good to name in a way that captures their purpose, which can easily become a bit long, or sometimes even very long.
So after I played with the remote and branch name auto-completion in Git Bash where it's automatically setup correctly, I made sure to set it up in all my home systems as well (here's my very recent article for doing this on a mac).
So yeah, Git auto-completion totally rocks, I should have done it sooner.