I own a My Book Essential 3TB. It works just fine so far on two different computers (one Linux, one Win7) and has normal transfer rates. However when the disk is idle, it still sounds like it’s constantly accessed - doesn’t sound like “click of death” clicking to me though.
I recently upgraded the firmware of the disk, this stopped for a while afterwards but started again soon afterwards.
Auto-spindown is set to 15 min and works fine.