"Upgrading" my Rainsoft

We purchased a Rainsoft "Classic Apollo Q" for around $5000 15 years ago. We are moving to a new home (finally) and the local Rainsoft company is telling me I can "upgrade" for $2190 plus a $350 installation fee. I didn't get a model name/number for them yet but they say it is "all composite, no brass" and comparable to the one I have but is computerized, uses less salt, and will not drop the water pressure as much. They claim that the system would cost $5900 new.

What questions should I ask to determine if this is a good idea or if I should investigate alternatives? They say we can leave the old one at the old house - doesn't have to be "returned" to get the discount.

Our new house is much bigger, but there are just 3 of us so consumption should not increase. The new house comes with a Rayne reverse osmosis system in the kitchen and line to the refrigerator so I'm mostly interested in avoiding the hard water problems. The new house is already plumbed for a water system and connecting should be easy.

Really appreciate any help or advise you can offer!