First off you need to remember that you will always find more bad user comments on line then good ones. WHY, because it is the bad experiences that upset people. I mean come on have you ever called a companies tech support because everything was great and you just wanted to let them know that. Of course not.
As long as the drive is of a recognizable brand has a decent amount of cash and has a good RPM speed you will probably be fine.
ANY drive can fail. ANY brand, ANY, size, internal and external. Just like ANY car can break down, ANY drive can fail.
Worrying like you are is pointless.