To calculate the overall star rating and percentage breakdown by star, we do not 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.
I just received this last week and use it in conjunction with my desk raised. The surface feels very comfortable and the build quality good. Fully satisfied. Had deferred purchase close to a year thinking it wont be all that important. But now feel I should have bought it long back. With regards improved back or leg health, I can right now only say that it makes you want to stand up longer and that is a start.