To calculate the overall star rating and percentage breakdown by star, we don’t use a simple average. Instead, our system considers things like how recent a review is and if the reviewer bought the item on Amazon. It also analyses reviews to verify trustworthiness.
The package contains everything you need, except the hard drives. There are even two screwdrives provided. For instructions you are pointed to the company website where you are walked through the startup process. The only thing not covered is the choice between Raid 0, Raid 1, JBOD and Single. For advice about that you'll need to look elsewhere.