I think it's a mistake to think Apple is superior. In 2006, 2007, and 2008 they had a pretty good price|performance ratio. But they didn't have "the best" design or even the best hardware even then. Apple is primarily a software house and at that they rock! At hardware not so much. Their cases and form designs are very nice tho! Their motherboards are pretty much by Intel. Nothing much under the hood of an Apple has much to do with Apple at all.
The PowerMac G5 Case and MacPro Case trump any pc case in design