i have a 600jb, an 800jb, and a 1000bb from western digital. great drives. i also have a maxtor diamondmax 160gig/8meg that i picked up dirt cheap ($0.61 per gig after rebates). and its an ata133(and came with a pci ata card). granted you dont see a hugh boost going from 100 to 133, but it does test higher than my 1000bb.