To address the original poster: I am very, very surprised that you'd find a 1Ghz PC to to faster than your 1.5Ghz Powermac. As a recent switcher from the Windows world, I've actually found quite the opposite. My 867Mhz Powerbook G4 run as fast, or faster, than my 2Ghz IBM thinkpad laptop. I'm not talking about raw crunching speed, I'm referring to real life performance multitasking, using multiple common applications at the same time.
I truly believe clock speed (Mhz and Ghz) cannot be fairly compared between PCs and Macs anymore... things have really changed over the past few years. Look at the new Mac mini, which is only 1.4Ghz: do you think people will care? They'll get better performance than a typical no-name clone for the same price, and more importantly, they'll start using OS X. The same comparison can be made with laptops.
Sometimes the grass seems greener on the other side... that is, until you get there and realize how good you have it with Apple.
Kelly