Does a book or a web page really know the information it contains?
Doubtful. If a book contains the equations, 1 + 1 = 2, and 1 + 1 = 3, how does it know the first and not the second equation?
I'm currently running a WD Green with an old Samsung SSD 830 as cache. I get the occasional pause if a game loads in something that isn't on the SSD. Overall though it's very fast with that combination and seek times, in particular, aren't an issue except for the first time you play a new game. A WD Black with an SSD as cache should be even better.
My statistical insignificant experience with HDDs: WD: Old WD Caviar died, but the replacement lasted years. Two WD Greens still working. IBM (Now Hitachi): Had one die, two others still work. Samsung: Both still working. Seagate: Never had any.