The Good The WD My Book Thunderbolt Duo makes a great alternative to USB- or FireWire-based external drives. The drive is relatively affordable, supports RAID configurations, and is easy to service.
The Bad The WD My Book Thunderbolt Duo's performance is comparatively slow. The drive doesn't offer any other connection types, nor does it include a Thunderbolt cable.
The Bottom Line The WD My Book Thunderbolt Duo makes a very good external storage device for Thunderbolt-enabled Macs thanks to its comparative affordability, ease of use, and decent performance.
WD My Book Thunderbolt Duo
The WD My Book Thunderbolt Duo is basically the Thunderbolt version of the My Book Studio Edtion II. The drive offers up to 6TB of storage space (in RAID 0) and very good performance for an external hard drive. Compared with other Thunderbolt storage devices on the market, however, it's one of the slowest.
To make up for this, the drive starts at a low $600 for 4TB and $700 for 6TB; that's about $100 cheaper than the similarly configured LaCie 2big Thunderbolt . Like with Thunderbolt storage devices, you'll have to spend another $50 for a Thunderbolt cable.
This lower pricing and the fact that users can replace the internal hard drives by themselves make the WD My Book Thunderbolt Duo a very good choice for people who want to enjoy Thunderbolt-grade performance without having to spend too much.