Look into Bosch. Replaced our KitchenAid after many years,have had this one for at least 10 yrs.
It's quiet for a dishwasher but the wash cycle takes a while.
Installed a new Bosch 800 series in our Idaho house. Quietest dishwasher I've never heard. It had to have a light so you'd know it was cleaning. We installed a new KitchenAid in our house here. I actually think I like it better than the Bosch. It's nearly as quiet, but not quite. It seems to do a better job of cleaning, though.
I'd say you can't go wrong with either. They do cost more than some of the other brands.
After learning that Whirlpool and Kitchenaid use the same pumps and stuff I went Bosch. The cleaning is hands down better than the Whirlpool Gold it replaced. I'm not as keen on the racks, but Bosch it is for me...
Last year we replaced a 19 year old Kenmore (Whirlpool) with a Bosch. The cleaning results are no better with the Bosch vs the Kenmore. The Kenmore cleaning cycle was one hour while the standard Bosch is 2 hours 30 minutes.
The Bosch is very quiet. It uses a lot of rinse agent.