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 is the 2nd one I have purchased of the exact same bottle, the first one lasted me heavy daily use of more than 2 years but just started getting scratched a bit so I thought it was time to buy another one. I like my water as cold as possible, even during the middle of winter (Yes, I am a weirdo)... I put 12 or so ice cubes in this bottle every morning before going to work and refill it several times throughout the day. Even when I get home in the evening it still has ice cubes left in it. Same if I put some in before bed, they're still mostly there in the morning. Well worth every cent.