is this new or used?
I bought two drives, both were packaged as new. I already have two similar drives, making a total of four. The serial numbers of the ones I just bought showed one with a larger number in the S/N, suggesting it was a newer lot, and one with a smaller number, suggesting it was from an older lot. One internal drive died in the "older" unit. Made me wonder if the "older" one was a refurbished unit? Adorama referred me to Western Digital. I contacted Western Digital requesting an RMA -- however as I had put sensitive data on it, I did not want to lose control over a damaged drive, and so requested a replacement without a return, and noting that I would shred (yes, they can be shredded) to failed unit. Western Digital has a policy to allow such an RMA without a return to protect sensitive data. I filed all the paperwork, but have not yet received the replacement in several weeks.
I bought replalacement internal drives, just in case, so I used the one that I had, and the new, expected one from WD will be my next spare.
I suspect that if I update the firmware, available from Western Digital, that the performance of all drives will be the same -- I have not yet done that.
Long answer, but given the serial numbers and the drive failure, I thought the longer answer more useful. Bottom line? I would recommend a buy. If the serial number begins with a "1" it's older, if "3" it's newest (my interpretation). I would suggest updating the firmware before you put any data on it. Adorama is the only place that I've found these drives that use Firewire. Both Adorama and Western Digital's customer service were excellent.