BS reply 
I simply dont believe that…
8sec cant be right value for any hdd in Linux system.
There is something else for you - with MyBook World Edition (whitelight) - these default 8secs results in very annoying click-click sound repeatedly from hdd - thats when heads trying to park but cant due some Linux process waking them up again. I did changed default value for MyBook World Edition also, and as expected “click-click” thing stopped immideately.
With MyBook Live you almost cant hear any “click-click” becouse hdd inside is more newer model and probably also due fact NAS unit does have more “cache ram” for doing little things without waking up the drive (for example i can use IRC from MyBookLive when hdd is in stand-by mode perfectly), and you can make them even more quiet as explined here - http://community.wdc.com/t5/My-Book-Live/Little-trick-to-make-hdd-work-even-more-quiet/m-p/142972#M1026
Edit:
Im not saying that reaching superb high value is not possible. It seems it is possible, becouse somebody from other forum sent me details about his WD MyBook (BlueRing) stats. Here they are:
9 Power_On_Hours 0x0032 072 072 000 Old_age Always - 20560
193 Load_Cycle_Count 0x0032 001 001 000 Old_age Always - 1151823
So… over 1 million cycles.
