I have the original dual 1.8 (8 slots, PCI-X) with the 9600 (64mb), 1gb ram, 160 and 200gb HDs, 8x superdrive, AirPort Extreme, Bluetooth 10.4.1 and a 20" aluminum cinema display. All I can say is that this has probably been my favorite mac to date. My only gripe is:
The number of HD slots, two isn't enough for me, and I dislike external drives. I didn't want my CD and DVD collections getting stolen at college, so I ripped all my CDs into iTunes (89gb) and all of my DVDs together amount to over 300gb (encoded into 1gb files) So half of my files are on an external drive, and the rest are on my 200gb secondary drive. I really wish Apple had designed the case to fit more HDs, rather than having to shell out $89 for an attachment and then another $89 for a SATA card. My old Quicksilver had 4 bays, and 5 if you count the zip. But I suppose that is the trade off, because my G5 is ultra quiet.
I have had a dual 2.0 with a gig of ram and a 20in acd since last august and i still love it, i have no problems with it at all as far as hardware and os x, just a few individual program crashes. I would strongly recommend it to anyone, and especially since it is the least expensive g5 system available from apple i would definitly get one or if you could afford the higher systems go for them, i could only imagine how amazing they must be.
owner of a dual 2.0 since last tuesday I love this thing, it destroys my 15" powerbook in performance (I do video work), but even in everyday things I notice a difference. I'm proud of my new powermac, I'll never buy a non-tower desktop again