Amazon calculates a product’s star ratings using a machine learned model instead of a raw data average. The machine learned model takes into account factors including: the age of a review, helpfulness votes by customers and whether the reviews are from verified purchases.
Not too bad. It’s very obvious that the parts used (ie. touch screen) are sub par in comparison to genuine Apple products. Definitely wouldn’t pay that amount of money again for a refurbished phone that has used mediocre equipment.