If you need one, then get one. They are not large and because you would install it it using three taps in order to provide a bypass in case of need to service it you can easily take it with you if you move house. We bought one 25 years ago and have taken it with us. Works as well today as new. I recommend buying a non electric one. An example is kinetic, others are available. They have 2 chambers in parallel, whereas the electric ones have a single chamber. The incoming water goes through a meter similar to the water company’s meter and after a preset amount has been filtered it uses the water pressure itself to close supply to one chamber and do the regeneration process (flushing a reverse flow of salty water through the chamber out to the drain, and then clearing that with a washout using clear water from the other chamber.) whilst it is doing this which takes about 20 mins, the house operates on very slightly reduced water pressure. The two chambers take turns to be flushed. It is maintenance free, you just have to feed it with 2kg blocks of salt. Electric ones refresh on a timer that typically are set to refresh at the same time in the middle of the night irrespective of water usage which is wasteful of salt and leaves you without any water whilst it does it. But twin chambers hydraulically powered are or were, about twice the price. As soon as you have one you will spend way less on all sorts. Less on washing machine detergents; turn off the softener in your dishwater, less shampoo, no descaling stuff for showers etc and no ball valves in toilets or tanks will furr up.