I'm unclear on why this recommends setting up a user account for every committer. I'm a big fan of simply adding each committer's ssh key to a single "git" user account to avoid the overhead of managing multiple user accounts--you have to make sure each ssh key line is identified by the user submitting it in case it needs removal in the future, but it's much easier to manage adding and removing users.

There are some additional configuration steps for that single user, but most are covered in the manual at http://git-scm.com/book/en/Git-on-the-Server-Setting-Up-the-...

Is there some advantage to separate user accounts that I'm missing?