This way, when things break or don't function how you like, you can easily copy the original config file back into position, restoring the original functionality.
I tend to make a .bak file before changes. There is nothing worse than fixing one config item only to realize later something else broke and not being sure what it was that changed and no easy way to revert. I'm guilty of having many .bak configs that are poorly named. I hadn't heard of etckeeper before. That looks real handy for me. Thanks for sharing