Right, what I'm saying is that personally, I would have hoped it was a Caviar Black series (ending in ALS like the 1 TB model mentioned), not the Blue series (AAKS models). In other words, this would have been my stock 640 of choice:
To quote them: "Do you want the fastest drive for a home computer? Take a Western Digital Caviar Black." But they liked the Blue for a server, so depends on your use.