I have had the Siemans Hydrosensor dishwasher for six years.  It is most definately the quietest, most efficient home appliance I own. It is so quiet that I sometimes forget that I have turned it on and have to open it to check and see if I did.  No pre-rinsing is necessary because the machine has a "Pot Scrubber" feature that leaves everything squeaky clean.  The downside of this feature is that the food catcher thingy on the bottom of the tub needs to be cleaned out regularly to avoid the stinkies.  I feel this is a minor inconvenience compared to the machine's efficiency.  I have tried...