Associate
There's been a few threads about this over the years. I have replied in previous ones but from my understanding all softeners are essentially the same. Companies like Harvey's will sell you a lot of marketing nonsense about twin systems etc but in reality softening the water is a chemical process and the big companies are hilariously over priced. I did a lot of research before installing mine and went with a tap works AD11 which I bought off amazon for around 400 quid then paid my plumber a couple of hundred to fit it. This included putting in a drinking water tap in off the hard supply in the kitchen. Everything else is softened. Overall one of the best things I've ever done in the house.