Stars that are used to rate hearing aids are often NOT REPRESENTING REVIEWS
These are instead arbitrarily placed next to hearing aid models as an opinion by the author only. You can spot this straight away as older models / lower spec. models will be marked with less stars, and the most expensive models with 5 stars.
In the last four years or so, it’s true that just like mobile phones and TVs, hearing aids have mostly been pretty impressive tech items.
So you can sometimes pick up a real bargain by going for a slightly ‘out of date’ model. I certainly do that with my TV and my mobile phone.