I have a 33yr old RainSoft system. Wayyy overpaid. Got taken advantage of being young and inexperienced. Installation was good, (in garage), but the system was designed for a family of four and there were only two of us in the house. The mechanical clock timer will recycle once a week at a minimum, which is far too often given the low water use.
FF a few decades on. Multiple local RS "distributers" went Tango Uniform. So I started working on it myself. Why pay some dude $100 + $65/hr. after the first hr to do work I can do myself?
Due to RS's lifetime warranty (anything that touches water), I decided to take it all apart, clean, relube, and replace all the seals. Cost me zero $. Then tried to fix a crack in the salt tank. No joy. Turns out RS warranted that as well. Got a new modern one. All because I still had my original receipt! Which was required. Of course, no one else had any record of my purchase, including RS.
I replumbed it using unions and ball valves, so I can remove it from the system and bypass it without cutting any PVC. I can also bypass it when watering from assorted hose spigots around the yard.
Due to my low water usage, and being sold a large unit, I now turn off the timer, set a reminder to myself every 6 weeks to manually 'regenerate' it. Works like a charm, saves salt and no dangerously slippery water.
Look at your monthly water bills (minus sprinklers) to determine how much water you use. Then have your water tested by a reputable lab so you have your own, independent test data. Now you know what size unit you have and how much water will go through it every month.
When you get it plumbed, be sure to use unions and ball-valves to ease maintainence and allow bypassing. If it's all solvent-glued in, you'll need a hacksaw to remove it.
As far as results, it's great! Water heater, dishwasher, clothes washer, ice maker, etc. all last & last. Clothes don't need fabric softener. They are already soft and last longer because there's no dried minerals in the threads. I wash the sled with soft water, then blow dry. It's taken me more than a decade to use a gallon of car wash....
Makes your hair and skin feel very clean. Shampoo & soap last a long time because so little is needed. You have to be careful in the shower & tub & also hand-washing dishes: they get really, really slippery. You'll get used to it over time.
So I'd get one again, but I'd shop around, cast a critical eye towards any salesman and probably assemble my own from quality parts via the web. Lots of info out there on how to roll your own if so inclined.
Beware of paying extra $$$$$ for softwater 24/7....