The Mac OS in its current state is a compromise, and Windows beats it on several measures:
Of course then there's the issue of Microsoft Office performance. Mac OS loses hands down here, with no credible argument from the Mac camp. Blame whatever you want--incompetent MS programmers, evil MS conspirators, differential investment in optimization, the use of "forbidden" APIs, etc, but the effect at the end user level is the same. Word, Excel and PowerPoint run 2-3 times faster in Windows. And for the user, that's important.
It would be great if I had the Mac UI without compromising on the speed and resource requirements. With OS X, it looks like I'll be able to :)
Thanks, and please come back soon!