This a great little hard drive, and very convenient for me after years of lugging round transformer powered portable hard drives. It works fine on my laptop when running on battery power, and transfer rates are generally good, on average about 25mb/s write speed. The USB cable is a bit on the short side, but feels chunky and secures well into the drive.
Only four stars because although the hardware is great, they bundle some rubbish WD Smartware software which I had to spend a couple of hours disabling and which cannot be fully removed, so you still lose 700mb to an inaccesible partition. Come on WD enough with the disabling tools its difficult enough for non-techies, this software should be strictly opt-in, not opt-out!