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.
The speaker works well when alone and quality of the sound is good. In my case, I configured a pair in stereo mode through wifi: it's not intuitive and require some IT skills. Then you can play sounds with your mobile device only through Bose application that you have installed ... and configured. First disappointment, it will work only with some sources. Second disappointment comes when a day, someone connect to one speaker through Bluetooth and it broke the whole configuration. I have to reset and redo the whole setup. As a conclusion, it looks to be an unfinished product: a good design supported by mediocre software. Maybe a future patch will fix that.