I've used two of these for several years (one on the counter and one in the fridge).  It is easy to tell when the filters are at the point of needing to be changed because the water (soup/coffee/tea) tastes "off".  Given all the pollutants in the water, it also gives me a bit of peace of mind to know my grandkids and puppies are drinking water that is filtered; there is no comparison with some of the other brands I tried!