[FFL]

I just bought a 320 from OWC, and it was a Western Digital Scorpio.

You can swap the drives in the OWC case, but it's not all that easy - the circuit board is held in there pretty snugly. An OWC tech once recommended making a loop out of a paper clip and using that to hook around a FireWire port socket in order to remove the circuit board from the enclosure.