Well, impressions of course can differ. I observe lot's of people moving from Windows to Linux, and never yet observed anyone moving from Linux to Mac OSX. But globally this probably doesn't mean much.
Honestly, this article made me realize how much I take it for granted that all of the LCD projectors and dual-monitor setups I've encountered in the last half-decade have just worked with my mac. I thought back to 1999, when I got my first Xinerama dual-head setup working with X11 after about 4 hours of work...
xf86config? Oh the pain! One of the video cards was running at 50hz in 15-bit color mode. Madness.