I found that the MacOSX installer will fail if the iMac G4 sleep functions kick in. For some reason the installer doesn't disable any of the power saver functions for the screen, hard disk etc so when (i assume) the hard disk or cd/dvd-rom (not sure which) powers down the installer will fail with an big orange error saying installation component not found.

My wife and I took our first DVD back as we thought it must be faulty. However after seeing the same error again, we watched carefully (rather than just walking away for long waits in the installer) we noticed that the failure varyied as to when it occurred i suggested that my wife sit there and hit ctrl ever minute or so throughout the 90 odd minute install (as ctrl has no impact on the installer, but will wake this system. this is an old unix best practise). So with a novel in hand she diligently tapped ctrl throughout the installer. It then worked nicely.

In my defense the upgrade of OS was to allow her new iPod nano to work. Panther was perfectly suitable for all other purposes, even if a few new apps were starting to not support it, it worked fine for browsing, watching files and dvd, and up until the new iPod nano - for syncing ipods.

As the install would start upgrading the system then fail, I was unable to get back into 10.3 to turn off power saver features. So the machine was basically a brick without sitting there tapping on the keyboard for an hour and half.

Good news is that despite the numerous upgrade failures, when things finally did install properly we didnt lose anything. All the user data and installed apps from 10.3 were where they should be and the upgrade is as you would expect. Ie everything is the same when you log in except the version is now newer and there are more bells and whistles.

Our iMac G4 is 1ghz with 768mb ram and Leopard seems to run just as well as Panther. There are a few effects that are slower and surprisingly some that are faster. For the skeptical windows user, you cant boast that sort of experience when upgrading windows ever. Although i will admit that moving from NT4 to Windows 2000 was actually the first time that upgrading windows seemed to make life better.