We got one because of the very hard water in AZ (50 grains per gallon) where we spent the winter and not quite so hard water in CO (20 grains per gallon) where we spent a couple of months in the spring and fall was clogging the faucet aerators, shower head and input filters on the Moen kitchen faucet with pull out spray wand. White crud was also building up in the plumbing.
For a year or more after we started using it we were still getting pieces of it breaking off from the PEX tubing walls and collecting in the faucets.