When I went from an 867MHz G4 (Powerbook) to a 1.5GHz G4 (also a Powerbook), the difference was fairly subtle for most types of use. Even going from my G4 to the current Mac Pro, basic things aren't shockingly different. IMO a G4 Powermac, with its expandability, is still a fine desktop. As a matter of fact, if I didn't need to run Windows apps for work, I may not have bothered to make the Intel Mac transition at all. That said, I do need to use Windows for work, have bought two Intel Macs to date, and am looking at a third (iMac for my dad🙂).