Summary: We got this dishwasher specifically because we wanted one that was super quiet. It's definitely quiet -- we run it after dinner and can't hear it 10 feet away in the living room. But...we've had problems with it from the start. The detergent dispenser didn't open at first and then we found that this is a common problem. Kitchenaid dispatched someone to replace the component within a week of purchase. So that was good.
Summary: I purchased this unit from a local appliance store that carries higher end items and bought a Kitchenaid refrigerator and stove as well. I love this dishwasher. It is so quiet I initially wasn't sure if it was turned on. I'm not sure if it is normally this quiet or if it had something to do with the new cabinetry. The tub is tall and accomodates almost twice as many place settings as my old dishwasher.
Summary: We purchased this dishwasher a couple of weeks ago from Pacific Sales in southern California (we got a floor model so got a great deal, though it did have a few dents in the back - can't see them once it's installed). It replaced a 17-year-old dishwasher, which I didn't think was especially noisy, but we definitely heard it running. This unit is incredibly quiet.