It won't be used for showering, bathing, flushing toilets, washing clothes, washing dishes, watering plants, washing cars, filling pools, or other outdoor water usage. How much does it increase a household's water usage?
I think that's improved, at least according to product literature (I haven't tested it myself), however:
The latest generation of small under-sink reverse osmosis filters claim to waste only 1 gallon for every 2 gallons of usable water. Still bad but much better than before.