AidenShaw said:PCs tend to be much more expandable than most Macs - many PCs can be upgraded to Longhorn's recommended configurations (add memory, or better graphics)
Mac's are eminently upgradeable too. I've used both for a long time (>20 yrs) and upgraded both many times. The Macs last a lot longer. This is born out by industry studies. Cost of ownership is lower on the Mac and length of service per machine is longer for the Mac.
AidenShaw said:Longhorn will turn off the eye-candy and other effects on machines that aren't up to the recommended configurations, and perform just fine
OSX does this too.