FWIW, modern HDD's have spare sectors in their low level format that are used specifically for remapping bad sectors in the user accessible portion of the disk.

Thus, if the drive detects a failing sector it will move the data to one of these spare sectors and map out the bad one. You will only see bad sectors reported by Windows or other OS's once these spare sectors are all used up. In which case it is probably time to scrap the drive - it's seriously on it's way out.

For this reason, while a long format can be a security blanket, I doubt that it has any real benefit.

--=-- My credo: If it's worth doing, it's worth overdoing - just ask my missus, she'll tell ya laugh --=--
You're only paranoid if you're wrong!