AO smith is a very unreliable brand due to its customer service and pathetic filter and AMC plans. I am using the product for 3 years and the water is fine but its customer service is completely not transparent and they cheat on filter change or AMC plans. I also have LG at my Inlaws place and it gives gr8 service and they call every quarter to service. My aosmith is under amc for 18 months now and not even a single call by engineer. When I asked them to change press filter as the site says it is good for 1000 litres, engineer came, cleaned it and left.
When product was in no amc they will change filters 3 times a year and when in amc they dont even change in 18 months.