To calculate the overall star rating and percentage breakdown by star, we don’t use a simple average. Instead, our system considers things like how recent a review is and if the reviewer bought the item on Amazon. It also analyses reviews to verify trustworthiness.
The product looks nice, is well made and gets very hot. However it's just a novelty and doesn't really keep my coffee hotter for any longer than normal. The problem is more with the mug you use rather than this product itself. You would need to use a steel mug, with a flat bottom and with no insulation to reap the benefits of this. They should sell this with the optimum mug to use.