I have only had this about 3 months but it still looks nice and shiny on the inside. It does a good job of grinding up the food.  I will see how long this continues to do a great job as I have replaced 4 Insinkerator brand disposals in the past 13 years from rust.  Insinkerators rust and leak from the bottom.  That is why I got this one that is stainless steel.  I sure hope it lasts longer than 2 or 3 years.  It has a 5 year warranty so it is already better than the other brands!