Mac9: Depending on what you're doing (say, what the majority of computer users use computers for), the "big Cadillac" is vastly more efficient than the Iyonix. The Iyonix just doesn't have the grunt to get the things lots of people want to do done in any timely manner. So you end up waiting and tapping your foot, while it spends longer and longer doing it, eating more and more power.
What technology does your RiscPC have that's way ahead of your PC? And wtf have you done to your PC that makes it eat a kilowatt? (My desktop, incidentally, is approximately 5 times the speed of an Iyonix, so quite modest in PC terms, and eats 140W when loaded.)