Interesting site, some of the stuff they recomend are really only neccesary on a slow machine. I have an 1800xp athlon and I can record 8 tracks of 96k 24 bit data with no problems, even with all the bells and whistles turned on.
Also, the ACPI stuff greatly depends on the motherboard. My board, I was able to get every thing on a sperate IRQ without any problems. I also did an upgrade install, and then later switched motherboards and chipsets(dont try this at home kids), and XP caught everything just fine and is running stable, except when i really screw with it. Since a big part of my job is screwing with new tech, and finding problems, my system takes quite a beating, and XP has held up admirably.