I think the two opposing camps are arguing about 2 separate things: one side is arguing about how many calculations per second a PC can do, about how fast its display is and how much higher res it has, or how much more bandwith and speed the newer busses have. The other side is arguing about what really matters: the user experience. This includes boot up time and the system putting you in control to do what you want to do when you want to do it. Personally I expected so much more than I'm getting from my current PC hardware running Vista. The hardware specs of even a 5 year old PC are insane, the average Joe's PC is more powerful than computers used in physics labs only a few years ago, yet it takes time to open a start menu, it takes time to draw the contents of a window, i have to wait for no apparant reason to pull down a menu even though an app has loaded.
When I went from my A500 with 3 meg ram to my A1200 40 mhz 68030 with 16 meg ram i thought WOW, now this progress!! And then I got an A4000 with 68060 and CV64 and I thought I was in Cray supecomputer territory. Just imagine i thought if I owned one of the piping hot 200 mhz pentiums...purely judging on mhz and necer used a PC before. What a joke things have turned out to be: my 3000 mhz C2duo runs general operating system tasks no faster than that 200 mhz pentium running Win95, and yet we still communicate with the hardware in the same way: by a mouse menu and icons. And yes Xp and vista are more complex beasts than Win 95, but this is NO EXCUSE because the hardware more than makes-up for the increased complexity of the OS. Sure we can crunch numbers faster, but the user experience is just as stop-start as it ever was.
My 13 year old son switches on his A1200 with a 68060, it boots in under 5 seconds, dpaint loads in 4 seconds and he's spray painting in real time in under 20 seconds from switching on. He asks me "Why don't they make computers like this anymore". He "gets" Amiga. And those of you who are happy with your PC, quite simply, don't.