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.
Using it on my Surface Pro 7. Installed some apps on it and the apps work fine. Data transfer is fast. A very good value. Highly recommended for Surface Pro users. Just put it in and forget about it. 400GB extra storage!!