Out of the box the drives are built in a RAID 0 (stripped) array for speed but you could of course re-build them in a RAID 1 (mirrored) array for data security, if you wanted to.
To access all the storage space the My Book Studio Edition II offers, WD has fitted it with four interfaces, three of which lean to the Mac side of things. You get Firewire 400 (up to 400Mb/s) and 800 (up to 800Mb/s), eSATA (up to 1.5Gb/sec) and USB 2.0. (up to 480Mb/sec). The choice of USB 2.0 is a major disappointment for Windows users, as the better USB 3.0 option has become a standard component on most of today's motherboards.
But because the drive is part of the Desktop for Mac family the answer is simple – currently Macs don't natively support USB 3.0. With the arrival of the Thunderbolt interface that is unlikely to change, but it's somewhat surprising that WD didn't include it for the sake of people using Windows Vista and Windows 7 (other Windows PCs don't support it either, thanks to MBR limitations).
Having to house two sets of four drives, the My Book Studio Edition II isn't exactly svelte. At 166 x 154 x 98mm (hxdxw), it makes for an imposing piece of desktop hardware, and if you wanted to carry it about you would soon notice its 2.63kg weight.
Thanks to Western Digital's own GreenPower technology in the drives, there's no need for a cooling fan in the enclosure. If a drive goes down or you fancy installing even larger capacity drives if they appear, Western Digital's made changing disks in the My Book Studio Edition II nice and straightforward, and joy of joys you don't need a screwdriver or any other tool to do it.
The huge capacity with a range of interfaces for both Windows and Mac users is brilliant, with the obvious omission of USB 3.0. To give you an idea of how much data a 6TB drive can hold, Western Digital claims there is space for up to 1,200,000 photos or 461 hours of DV formatted video or up to 1,500,000 MP3s.
While we understand Western Digital's decision to not stick an USB 3.0 interface on the My Book Studio Edition II because they have aimed it primarily at the Mac community, it still seems a bit mean not to add it on the drive, as Windows users are certainly going to want to use the huge capacity the drive offers.
Stunning capacity with a range of interfaces for not that much more money than two bare WD 3TB drives, and the five year warranty is handy too.