I have this unit since 2000 and it worked without a problem. (Now I am doing a major refit so I have not used in the last 5 years.) The first 6 years it was used on a circumnavigation and worked without a major problem (Had to change one filter and once disassemble the HP pump and clean it)

I never measured the PPM however the water taste is great (same level as bottle spring water!) The actual output was around the 6 gallon per hour (where it should be). It is a 24V unit and installed under the berth in my pilot house with a large window for switches and gauges that allow the noise to get out. It does make noise but not excessive, just noticeable when working.