[kelnos]

I think it kinda doesn't matter in this context, though. You can pick up enough in an afternoon to be productive in a new VCS. If I worked at a Mercurial shop, I wouldn't disqualify a candidate that had only used git.

But sysadmin'ing Windows vs. Linux is basically two different jobs. You certainly wouldn't hire someone to be a Linux admin who'd only worked on Windows servers before.