Downloaded hours comparing different external hard disks and their performance. Overall, WD discs seem to have better reliability than Seagate according to all forums and reviews I read. The choice was between this and a Seagate Backup Plus Desktop Hub 8 TB because it has two USB 3.0 ports that you can use. However, it is a SMR hard drive which has its pros and cons. Slower writing but faster reading. Performance, however, seems to be equivalent to the WD My Book.
As soon as I got this, I did a Crystal DiskMark test and was reading about 180 MB / s and writing at about 170 mb / s. So I am very pleased. It was even faster than my internal Seagate 3 TB disk which I think is striking.
Have just had it for a few days so can not tell anyone about the reliability or the accompanying programs but the disk is very quiet. To get full points, I would like some extra USB 3.0 ports.
Note that performance can not be compared to the smaller external disks that power from the USB port, such as WD Passport. These are at best at around 120 mb / s in performance.