I bought a dell portable 2tb external hard disk with usb 3.0 .
I have used this product over 2 years and till now it responds great.
Transfer speed is very good.
Never shown any problem.
Very light weight as compared to other hard drives.
Even I can use this hard disk in my smartphone as an external drive.
Although it gives 1.8 tb out of 2 tb .
But that is more than sufficient.so it is the best product if you are searching for a good hard disk & worth to buy it.