Product reviews are supposed to be a neutral signal, but brand recognition quietly biases how people rate products - the same item often gets rated higher under a familiar brand name than an unknown one, even with identical quality.
A well-known brand's reviews tend to run more favorable partly because of reputation, not just product quality - worth mentally discounting slightly when comparing against a lesser-known brand's reviews for a similar item.
A review describing exactly how a product performed in a specific use case is far more useful than a generic five-star rating with no detail - specificity is a better signal of genuine experience than star count alone.
A 4.8 rating from 12 reviews carries far less statistical weight than a 4.3 rating from 3,000 reviews - a large volume of decent reviews is often a more reliable signal than a small volume of excellent ones.