The G5 DC's are air cooled so you don't have to worry about leaks killing a system. The things I hate about the PCIE models is lack of decent working video cards other then the slow 6600 crap they mostly came with and the expense of built in wireless (cards are cheap but you need an unobtanium adapter to use them).

The plus side is you can use cheap DDR2 RAM for 8-16GB (not sure what you would do with all of that). Sucks there are no PCI-X slots on the DC's since you can't use high end G4 capture cards (or on the cheap PCI only G5 models either).