I've had a Nuvo H2O plus taste in my home for over 5 years. I chose the Nuvo over traditional salt for a few reasons. I don't want salt in my water, I didn't want to waste water with the salt system backwash, I didn't want to put salt into the city water, I wanted something smaller in my garage, I didn't want to have to plug it in and run electricity, I wanted something that would help my appliances, I also wanted something that would help with the chlorine taste in my water and salt systems don't do that.
The Nuvo H2O to set clear expectations for those looking (I am a licensed plumber) will not remove calcium from your water, it transforms calcium so that doesn't stick to surfaces. If water falls on a flat surface and dries you will see the white ring, but it wipes away with a damp paper towel vs hard water that has to be rubbed away with vinegar. It will descale your plumbing over time, not overnight. It will, by descaling, extend the lifespan of your appliances. Don't believe it? By the packet from Nuvo, take a before picture of your dishwasher and then take an after picture once you've used the Nuvo packet as described by the manufacturer.
I always know when it is time to change my Nuvo filters because my dishes begin to spot again and my water starts to smell like a pool! There is a dramatic difference in the quality of my water with and without the Nuvo.
Be mindful if you're looking for a Nuvo H2O, make sure you have a water softener loop. If you do, make sure that loop is tied into your kitchen sink or you won't notice a difference in taste at your kitchen on the cold side and you'll be disappointed. Make sure that your system is installed with bypass valves. The Nuvo does not come with an internal bypass so if it leaks or if you need to change the cartridges you will have to shut off your whole home in order to do that or to eliminate the leak if something goes wrong with the Nuvo.