I received clear advice on the difference between the two products I was considering. Very quick delivery. Installation and set up took just under 2.5 hours which as what we anticipated. I chose this RO system on the basis that it has a post filter which I understand is meant to add back calcium and magnesium (and possibly other trace elements and/or electrolytes including potassium?) but cannot obtain clear information from OsmioWater on exactly which elements and in what approximate quantities (even given temperature variations) that they may be added back to the filtered water. I also have not been able to find any information that shows that a silver impregnated activated carbon post filter would actually add anything back to the water after the previous filters. Given my concerns on this I may be disconnecting this RO filter system and looking at other options to ensure that essential elements can remain in my family’s drinking water.