Western Digital's MyBook Premium ES is the eSATA version of this product family. But it also has a USB-2.0 interface for PCs that support USB 2.0 storage devices.

The MyBook Premium ES comes with Retrospect Express 7.5, which is more powerful than the Express HD software bundled with LaCie's drive. Not only does it cover typical backup applications including full and incremental scheduled or direct backup, but it can also clone entire hard drives.

When you shutdown your PC, the MyBook Premium ES will also spin down the hard drive and automatically switch it off. The remaining power requirement of 3.2 W is required by the power supply unit. Yet the 10.8 W idle power and the 12.5 W max power when the drive is active are the lowest results in this roundup. At the same time, this drive is the fastest one as well.

The MyBook family with its book-like exterior has been around for a while and isn't quite new, but its design still remains sleek. The downside is that the device cannot operate in environments hotter than 35°C (95°F), which is due to how this product lacks active cooling. There are plenty of ventilation openings, but the drive might still get too hot during midsummer days or in extreme climate zones. Be sure to keep an eye on the drive's temperature during operation.

We did not understand the warranty terms of Western Digital, as the MyBook Pro (see next pages) comes with a three-year warranty, versus a one-year guarantee that the eSATA MyBook Premium ES offers.