Thanks for the info! I used smartctl under Linux and viewed the IDENTIFY DEVICE hex data. The model number correctly appears in words 27-46 as per the ATA8 spec, so it would seem I am looking at the correct data.
However word 106 (physical/logical sector size) is zero, as are words 117-118 (words per logical sector).
You mentioned in the linked thread that this information is optional, so I guess WD chose to omit it from these drives for some reason. This is a shame, as one of the reasons why I chose this drive was because I wanted to try out these 4k sectors to see how my system behaved. Maybe I should just return the drive? Seems a shame when there’s nothing mechanically wrong with it, but I’m guessing there’s not much likelihood of getting a firmware update any time soon to fix this… 
