Lets see you compare performance between MacOS and Windows with a gigantor InDesign CS document and still say that.

Adobe products tend to run better on macs, but Windows is better for most other commonly used software. For example, just about any game. Furthermore when you compare price and performance apple computers cost more for their performance than a good windows-based computer (from a decent company). Pretty much unless you're a graphics designer/artist there aren't many reasons to buy a mac.

Before anyone starts whining about spyware and viruses that's not a valid argument as anyone who knows how to use windows worth anything shouldn't ever get either.