I've used Ubuntu as recently as 13.04 and I've used multiple iterations of Mint. For me they are fundamentally unpleasant to use. GNOME is an eyesore with visually unappealing applications sorely in need of UX help; KDE is worse. Oh, yeah, and OS X handles four monitors on two graphics cards without breaking a sweat, on a Hackintosh. Ubuntu and derivatives can't handle that without multiple X sessions and the couple hours every other month I have to spend updating my Hackintosh are worth the time for that alone. Even Windows isn't as crippled as Linux is here.

I haven't touched on software, either. Audio software is a mess on Linux. (Ardour, against the combination of Logic and Ableton and Reason? Ever having to configure jackd, versus Core Audio which literally just works? Why spend the time?) Programming software honestly isn't a ton better unless you find "live in Vim" fulfilling and while I used to do that, I'm much more productive in more modern software. Swing apps--i.e., IntelliJ--look like garbage on Linux and there's nothing on Windows or Linux that comes close to Xcode for C++ development.

Perhaps you should reserve your "challenges" for folks who haven't been there, done that.