Runs fine to do what?!? I am fairly disappointed with the performance of my Mac Mini...I bought it on the day they came out since it was finally hardware I could afford that would let me switch to Mac OS X (I sprung for the faster processor and 512MB of RAM). And yes, it works, but it isn't nearly as zippy at doing anything as any of my older boxes running Linux or Windows XP. I upgraded it to 1GB of RAM, which helped a little, and I still use it as my primary machine to check email and browse the web at home because I like the whole OS X user experience, but come on, runs fine on anything less powerful than a Mac Mini? Maybe you just haven't seen how other operating systems perform on various hardware so you have no point of reference to appreciate just how slow Mac OS X is?
Make no mistake, I'm not fan of Windows. But I'm also being completely realistic when I say that its hardware requirements, when the rubber meets the road, are more forgiving than Mac OS X.