If I was to by chance get one, would it be better to go with a 533MHz Dual Processor or 733MHz model? Are the graphics cards upgradeable in them? If so, to what? Anything AGP 4X? Also, I've read that the maximum IDE hard drive size is 128GB. Don't the PowerMacs have Ultra ATA/66 in them? So will this effect me if I want to upgrade with a Ultra ATA/66 hard drive that's above 128GB? I'm a bit confused on this part. Also a random question to be answered... I've been wondering: Do the metal PowerMacs and the MacPros have a fold down door like all the previous models? Thanks to anyone who can answer these for me!