Git is good for tracking changes, especially when working with more than one person or machine. It shouldn't slow anything down most of the time, it's pretty quick to do a commit/push and if it's a large one, it can run in the background. I try to use Git in any actual project I work on (so not little test projects) and it helps with a lot of things. Especially if I ever decide to have other people join the project. Even alone though, you can easily see what you changed and worked on at any given date/time and revert changes, keep track of releases and branches, etc.