It's better to use Unix centric programs on Unix operating system, but I run a lot of stuff on my computer that just can't be run by anything other than Windows. And to play games you'd either have to buy Cedega, or hack into Cedega, since DirectX obviously won't run native on a linux system. OpenGL will, but Microsoft put billions behind DirectX (at a time whenever it sucked, and OpenGL was by far a better interface) to catch up to OpenGL, apparently just so that they could have exclusive rights to it, which would prevent most games from running on other operating systems.
Still, Linux should be exactly the same thing as modern macs. You even have the same kind of processors as PC's now. This, ironically, makes the MAC IBM compatible, and therefore a PC.