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.
This unit like the rest is great, Unfortunately mine started peeling the red however I use it heavily and it is treated a bit more roughly. I have another unit in gold which doesn't scratch as easily. Cold water stays cold, hot water stays hot for a good 24 hours.