Not sure about the "scalewatcher" thingy, but here in the western U.S. we have exceptionally hard water. Soap doesn't "suds" and iron rings are left at the bottom of the toilet. We use the automatic salt type "whole home" type and it's worked well for years. It takes about three 40 pound bags of salt a month, but you get used to the schedule... just like any other maintenance job.
Nice thing is, it has a by-pass valve that one moves if you're going to use the water system for, say washing the car or watering the lawn. Saves the softened water until you move it back again.
Realitively inexpensic=ve to install... as I remember ours was about $500 (US).
Only other chore with it is to clean the resin bin once every couple of months. simple... just as a premixed chemical and run it thorugh a recycle...
You'll hear horror stories about added salt to the water... high blood pressure, etc. but a little education reveals any risks are minimal and one can elect to use potassium chloride rather than the salt pellets... somewhat more expensive but not much...