At 7 years a crack developed initiating at the flush handle that slowly extended down the tank over time. I assumed that the nylon nut holding the handle had been overly tightened at install, and replaced the tank at my expense. At 8 years (present) a very long crack has developed across the front of the bowl, in an inverted T shape from the rim down front and around to both sides but not extending to bolt locations at the base. It is in a master bath of two average sized adults in a well-cared-for home. This indicates a material flaw, not user error.