Rated 5 on Timeliness because they were found right after my 55 gallon water heater broke and I needed a better solution to hard water ruining parts. Found information I could understand. Liked smaller foot print of unit. Liked small unit for condo/town home in senior community of Las Vegas. My water heater blew in first 6 months of living here. Discovered, researched and ordered product and had someone install system as well as new On Demand water heater at the same time. Fitting into a ~30 year old house made for a somewhat convoluted piping sequence, but not NuVoH2O problem, just the way layout caused things to be installed.
I conserve water, electricity and whatever I can, so was surprised as time approached for 6 month cartridge replacement and had not used the suggested 10,000 gallons. But, do shower after swim at community center. Don't do dishes as often as others might. Don't cook much, etc. It took around 5 years to reach the website information on the cartridges that stated 20,000 or 6 months. Did not realize that was larger Home or Duo size cartridges.
Installed my first replacement last year with knowledge assist from plumber that was working on a sewer blockage. No mess, no fuss, enjoyed knowing I could do it myself whenever needed.
Signed up for Autoship every 12 months and ordered a single "extra" cartridge in case of heat/cold damage, leaks or anything where I may need to replace before next shipment.
Lived off community well water in Texas and know I still see spots of washed and air dried dishes, but not the completely white kind from earlier homes. I filter water with a Brita 6 month cartridge in a pitcher and have no problem with the water taste. Temperatures in my garage are often over 105 degrees but have not had problems with 7 year old unit at this point in time.
Like the cost, of original unit and installation, efficiency and reliability of filtration, ability to self install cartridge. Would tell anyone, but advise to follow web site advice and check your water hardness before buying a unit, in case it will not meet your needs.