I dismantled my quad core extreme edition PC to sell and buy a mac pro - this model. To look at it is a thing of beauty, its a lot larger than I thought it was, but still beautiful. It boots up quickly and is noticeably quicker than my imac core2duo 2.4ghz. It is able to burn disks very quickly and can run window. The mac pro was easy to set up; my only problem was that tiscali do not support apple; therefore I had to install the n wifi; it connects to the wifi with no problems and reaches optimum speed despite not being directly connected. The mac pro is also upgradable; and with snow leopard round the corner I just bet it will be superfast (more so). I cannot say everybody should have one but I wanted a pc that would last several yearsand would not crash like windows often does.
I am not anti PC; I built all my PC's from athlon 2000xp, pentium 4's pentium 4 extremes with pentium 975 extreme overclocked to 4ghz - then onto core2duos and quad cores with windows 95, 98, 2000, xp (home, media & Pro) 32 & 64bit, vista 32 & 64bit. Therefore I think I am entitled to comment about my exploits between the two standards.
My only criticism of the mac pro is that it uses a 1kw power supply; the mac pro is almost silent even when demands are placed on (and it has) but the amount of heat it emits, no need for a radiator I can tell you.
would I buy it again - yes without a doubt. I can think of only one criticism but lots for my old quad core and PC's in general. I would never buy or build a PC for myself again.