Tiger on my 500 MHz Beige G4 feels insanely fast to me even though I'm used to a (also extremely fast) dual-core Vista box as my main machine
Though I suppose it's just because I don't end up comparing the two different OSes directly - if I installed OS X on the PC then the G4 would probably end up feeling slow as I would start making direct comparisons between the speed of the OS.By the way, Tiger is generally thought to be slightly more optimised than Panther, especially for AltiVec. However, the AGP G4 can run Leopard with only a very simple tweak of the install DVD, and that's what I'd do if I had one!
