The styling and design on both units is good and both of these units offer a stackable and compact setup. There are two very clear differences between these external hard drives. The Iomega Triple Pro has three connection options with the fastested of which being the Firewire 800 infterface. The FW800 is almost exclusive to MACs, most MACs actually come standard with the FW800 port and since MACs have been favored in the video and audio production world, the high speed of the FW800 protocol could be the single selling point. The WD MyBook is a speedy and attactive 7200rpm hard drive but the Iomega is a bit bulky, requires AC-power and is slightly more in price.

In choosing consider the speed you're going to need, If you work consisently with large files then you're most likely going to want the Iomega, however the WD MyBook 500GB has a 16MB buffer memory while the Iomega has only an 8MB buffer which means that using the WD MyBook for music files and other smallish random files will work better than the Iomega whose smaller buffer is more suited for large files.