Product review (1 stars): High Cost, Low Quality Rubbish
Having owned dozens of dishwashers over several decades, I can say with absolute certainty that my Miele Optima is the worst kitchen appliance I have ever purchased.

Due to the high cost and the Miele name, along with assurance that the machine would work for at least ten years, I had expected to be extremely satisfied (Note: The 'ten year assurance' is not a guarantee, and is certainly NOT in the warranty)  It is certainly a sleek and smart-looking machine, it is very quiet while washing dishes, and it is very easy to operate.  The utensil tray was a very nice addition, and it felt like the machine could accommodate a large number of dishes.

That honeymoon phase lasted mere months before this machine started showing its true colors.  First, pre-washing by hand is mandatory.  Any stray particulate of food, including stains, grease, and other dirt, must be completely cleaned and scoured from all dishes before they are placed in the dishwasher.  The water jets are both extremely weak and poorly placed, and will not clean any food residue from dishes.  Period.  The jets also are arranged so as to give a direct application of clean water to only a small portion of the middle of the machine.  The utensil tray, located against the ceiling of the machine, will receive no direct application of water or cleaning chemicals if there are any dishes or glasses placed in the middle rack, blocking the stream of water (you can either clean your glasses and small dishes, or you can clean utensils, but you cannot clean both at the same time)

The pump which removed the soiled water from the machine after running a cycle is also very weak and shuts down too soon, leaving a large amount of the dirty water remaining in the bottom of the machine after each cycle.  This warm, dirty water promotes the growth of mold, bacteria, scum, and stains on the inside of the machine.  Never have I had a dishwasher which required so much cleaning and scrubbing of the machine itself just to keep it sanitary!

The Optima series also comes equipped with numerous state-of-the-art sensors and detectors, which measure everything from the temperature of the incoming water to the pressure within the pumps.  These devices trigger an error message whenever they detect a problem with the machine.  These sensors are so fragile, so high-tech, and so sensitive that they fail more often than they work.  Possible causes for a malfunction that I have experienced are: the temperature of the water in my pipes falling to a cool 45 degrees Fahrenheit, a warm, humid day disrupting the sensors, using a half-teaspoon too much soap, and the presence of particulates in the water (such as exist in all public water sources) damaging sensor equipment.  Failure to clean certain filters at the proper time will also set off these sensors, but cleaning said filters may also unintentionally trigger other sensors.  Most often, though, the sensors simply malfunction of their own accord, resulting in an error message.

Every error message will shut down the dishwasher, and prevent it from starting again until it has been serviced by a Miele repairman.  A single visit runs around $150, just for an observation of the problem.  Repair and replacement causes the actual cost to skyrocket.  This happens about every three to five months (I see Constantine, my Miele man, more often than I see some friends and family).  No such errors, problems, or mistakes with the sensors are covered under the warranty (and they always are mistakes, I have yet to experience a valid error message)  Owning an expensive Miele machine is not a one-time investment; each year your checkbook will feel like it has purchased a whole new Optima dishwasher.

Now, mind you, I thought for a while that I had just got a lemon.  Surely it's just my dishwasher that was poorly constructed, and any other Miele wouldn't be suffering from these issues?

No, I was informed that my machine was working as intended, and that these problems are a standard feature on the Miele Optima.  Both the repairman and an acquaintance who own the same machine confirmed that the faulty sensors, the weak pump, the pathetic water jets, the dirty and scummy interior, and other smaller problems are all part of the Miele experience.  Buyer Beware.

I would also be remiss if I didn't mention the end-of-cycle buzzer.  Upon completing a was, the machine will beep.  And beep.  And beep and beep and beep until someone goes over and powers down the machine.  In fairness, the first couple times the beeping sounds, it is not too unpleasant.  The problem is that the machine will not stop beeping.  There is no time limit to the buzzer, it will not stop beeping after a minute, after an hour, or after a week.  It will continue to screech at you until it receives attention.  And the buzzer (beeper?) is loud.  It wakes the children on the other side of the house when I run the machine at night.  If it goes off while watching a film, I will need to interrupt the movie to turn the machine off.  I have to schedule my dishwasher time so that someone will be around to turn it off when the cycle ends.  I can't run the machine before leaving the house for an evening out, because I'm afraid of what the hours of beeping will do to my pets.

Pros:
-Sleek, clean exterior
-Quiet (on the occasions when it does work)

Cons:
-Expensive up-front cost
-Frequent, expensive repair bills
-Weak water jets
-Poor water coverage of dish racks
-Does not scour or remove food particulate
-All dishes must be hand-washed and scrubbed before being put through washer
-Water marks and soap stains are to be expected
-All dishes come out wet and must be hand-dried
-Frequent cleaning of interior of machine is required
-Weak pump does not remove soiled water from bottom of dishwasher
-Interior takes on a foul, unpleasant smell after very few washes
-Faulty technology causes machine to malfunction often
-Constant pricey maintenance required
-Loud, obnoxious end-of-cycle buzzer
-Bad warranty conditions