Reading this I'm glad I'm working on Fedora.: one git per package, one tool to rule them all (fedpkg), one tool to sync them all locally (grokmirror), (relatively) easy global changes through proven packagers who can ask for mass changes before each release. I don't know how I would do it if I had to deal with svn, mercurial or no scm at all. I understand the want of being decentralized but this is being done at the maintainers expense, who are often already stretched thing.