Have been using this since last 2.5 years. It comes with 500 GB storage capacity and data protecting software. I haven’t faced a single bad sector problem in this till now.
Reason is also this that I have used it very cautiously and didn’t let it fall even once.
It is small and light in size thus pretty portable. It comes with 3 years manufacturer warranty. I registered it on Sandisk portal day I bought.
If you want 1 TB storage capacity, you can go for 1 TB External HDD as well but go for Seagate only.