Yes. I do. Unfortunately it doesn't support your average corporate workflow and requirements of centralisation very well (it can do it but its not its primary use case). The desktop tooling is also crappy and hard to get non-code-monkeys using it. We use svn for documentation as well and our windows users quite happily edit word documents collaboratively on top of it.
I stand baffled. Always thought Word and Excel files were binary files, thus almost un-mergeable in any useful - collaborative - manner.
Sorry for my misunderstanding.
I'm sorry with the poor assumption... But you started this thread with "Github downtime is the reason we can't use git internally" <--- This illustrates either you don't understand git very well. OR you don't understand logic very well.... I was giving you the benefit of the doubt on the latter... :\