I'm glad you think you know what you are talking about, although you do seem to have a lack of objectivity on the subject which promted me to reply in the first place.
a PC is a Personal computer, thats what apple make.
you pay for what you get, and what are they underpowered for? the G5 is for the most part a far better performer than the P4, the interface is great and smooth as hell (being acelerated by the graphics card), the windowing system sits atop...