I wanted to download msysgit here, and it says this: \"here are not enough contributors to the msysGit project to offer commercial-grade support; if you do not have the means to
The quote you mention is referring more to problems that you create. A huge purpose of "commercial-grade support" is to have someone to contact when you can't figure out how to dig yourself out of the hole you dove into. The developers naturally can't and have no desire to fill that role, and that quote is really just them trying to fend off waves of emails from people saying "I ran git clean -xdf and all my files are gone! Help!" An actual bug report would be a very different matter - they want their software to work just as much as you do.
All that said, msysgit is based on the git everyone else uses, which has a pretty extensive test suite. I think you can count on it for stability as much as you can any VCS at this point.