To help explain reliability, I would like to draw attention to figure 1.1. In figure 1.1 you can see how over a length of time that the failure rates remain low on the bathtub curve and the failure rate will begin to increase due to wear using time-based routines. https://goo.gl/472549
For anyone who plans to buy a piece of hardware, the overall reliability of the hardware should be high on the list of priorities. Unfortunately, much of the information that people use in deciding which product to buy is fragmentary and anecdotal--not the kind of data you'd want to base a three- or four-figure decision on. To illustrate reliability figure 1.2 shows a survey from 2009 about the most and least reliably hardware. https://goo.gl/kXao9Q
