A rating of 4.8 from more than 500 reviews sounds solid. On this page it is a number without an address.
There is no link to a review platform, no star-by-star breakdown, no dates and no explanation of how reviews are collected or filtered. We cannot say who counted them, over what period, or whether the 500 includes every submission or a selection.
A brand-displayed rating is a claim by the brand about its own product, however sincere. It is useful as a mood indicator, not as evidence.
Give it little weight on its own. Look for reviews on a platform where you can read the full range of scores and the text behind them, and for details such as timeline and what changed. Above all, run your own simple log, since your result is the one that matters to you.