I also voted only once, citing (my principal DT machine) a 17" "Igloo", PowerPC G4 (3.3), 1 GHz, running 10.4.8
My Aluminum PB is a PowerPC G4 (1.5), 1.67 GHz, running 10.4.8
My wife's DT machine is a 20" iMac, PowerPC G5 (3.1), 2.1 GHz, running 10.4.8
We also have a Pismo – PowerPC 750 (83.2), 400 MHz, as an "archive" PB to deal with old, old files from equally old apps. It's running 10.9. on one partition and I plan to try 8.6 on a second.
NB: "Main" is a relative term.