To anyone out there who would denounce this article as uninformed, let me say this; to limit yourself to a single operating environment limits your flexibility and exposure to what may be a better solution to any problem you encounter. Microsoft has done amazing things with Windows, but for some tasks, it is not the best solution. IMHO, I think Apple has developed the best workstation operating system in Mac OS X. As a server OS, it works OK, but both *nix and Windows will outperform and offer more features on more flexible hardware. But Apple has developed the best development environment I have yet to use. And to make it even better, my wife, mother and grandmother (who are all equally computer-ignorant, and want to remain that way) can use the same operating system to browse the internet, play their music and make home movies.
Just like the author, I keep a Windows box under my desk as well, for games and such. Between the two, though, the Mac has paid for itself, the PC box it sits next to, the servers I keep downstairs, as well as paying for the house I live in and everything else I do in my life.