You can actually get rid of the external firmware (the built in applications) and reclaim the space. IMHO no hard disk vendor has a monopoly on producing perfect disks - the best solution if one is really paranoid is a NAS configuration along the lines of a Drobo 5N device with mirroring.
What im talking about is how the MyBook's store the partition map on the enclosure controller, if you remove the hard drive from that enclosure and connect directly to your SATA internal connection you will have to re-initialize the drive (re-partition) in order to use it.
and the VCD is also stored on the enclosure controller and you can not erase it only disable it with the Smartware software so there is no space to recover.
Not only that I have had nearly every external WD drive i bought over a 3 year period (6 total, 4 failed) have some major malfunction by the time they were around 1 year old, im guessing mostly because the enclosures do not have fans and drives themselves don't have a very good tolerance for heat.
I finally switched to Seagate externals, have not yet had a failed drive in 2 years, and even at retail price direct from seagate the externals are cheaper than the internals of the exact same drive so even if you need an internal its cheaper to get an external and rip it out of the exclosure, not always the case with WD