Seagate is worst HDD brand. Review on Seagate Expansion Portable 3.0 1 TB

I speciaIy buy for upgrade my pc memory and also carry lots of data. I  bought this product at a local computer store and this price is about 4550 only.this hdd best part is it has 3.0 usb so I can easily transfer data at high speed.Its work very well I use this hdd about 6 months and no problem ocure. hdd wire quality is very good and its size about approx 1.5 feet . I choose this product because every one like my friend and my teacher  says that seagate is best brand . but its size is little big .build quality is good.and its don't create any noise when running and also dont heated.i use this hdd about 7/8 hours continuously.so friends this is good hdd you can buy.when I bought this hdd, I doing lots of experiment .like online video review and online price But after using some month now HDD create problem and the problem is speed is very slow.so I give the HDD to seagate service center and they solve the problem, and now HDD are not showing in computer so now one more time I face problem.and if I go to service center my all data will be erase, so two time my data is totally lost.