Hello
I though Id add what I did. I have a G4 mirror door Dual 1 Gz. don't know the manufacture date, with a ATA66 and ATA33 drive sets. two per set.
Fry's Palo ALto had a recent Hitachi/IBM deskstar rebate for the 250 GB HD to a final price of about $120
I put four in, two at each site. after much fiddling and cloning of the original 80GB HD to get the OS to boot from the new HD, things are fine.
I have AlchemyTV DVR and its taking a lot of HD space, and I have a miniDV Canon where I passs through old VCR tapes into iMovie and make DVD's out of them
of note: I had an old LaCie firewire drive with a 30GB drive in it. tried the 250 in there and got the 137/128 limit.
LaCie said there was a 'bridge' in that drive that limited things to 128 I had assumed that meant a physical item so Id never get more.
I put an old 80gb from the G4 in there and it works fine.
rotut