The G4 is 800Mhz Quicksilver 2002 model (Mac 3.5) it does the job reasonably well actually once I sorted the sound issues. In fact all I need is internet and I could live with this. Minor slowdown when running games in E-UAE but thats probably not a surprise.
The G5 (a 2.0Ghz DP (A1047) with ATI Radeon 9600, 4GB RAM, PowerMac 7.5) was a clean install of MorphOS 3.9 but it seemed to regularly freeze. Sound would work intermittently. Sometimes it would be fine other times it just refused to initialise.
It also seemed to be running exceptionally warm, now I know the G5 can be a power monster but it runs OS X without almost melting down.
I also could not get the E-UAE setup working no matter which setup I used. It would acknowledge the HDF but refused to allow the filesystem pickup which had many WHDload games. Ironically the G4 did this no worries but the G5 just would not play ball.
Now that's not a fault of MorphOS probably my incompetance.
Several programs that worked on the G4 such as Poly Organiser worked on the G4 after a bit of library installation on the G5 it would not and I installed the one missing library it refused to acknowledge it.
Also I could not get the Airport card to connect and stay connected. This is probably due to my network being WPA2 so it just connected and disconnected. Setting up DNS servers refused to work even when it did connect.
I have been playing about for weeks and although it has been an experience I do believe that MorphOS has a bit further to go before I consider it worth paying for.
/gets off soapbox