I don't know if this is a switch, but:
Always had PCs, but I got a Mac at one point about two or three years ago, used it (in conjunction with my PCs, running a variety of Windows and BSD operating systems), and decided that it wasn't for me. I just didn't like MOSX at all - I saw no need to pay the extra money to buy PPC hardware to run it, plus I didn't like the GUI (though I could have ran my own - but then what's the point if I'm paying for a Mac?), etc. Also, I'd rather use my money to buy upgrades to let me play more games than to get the newest & greatest Mac, which wouldn't let me play so many games.
Still happily using WinXP, FreeBSD, OpenBSD, and Gentoo.