Amazing that you can buy from Amazon this machine still here. However, this circumstance can in my opinion be the cause that some buyers have problems with leaking seals in their 'new' Prima Donnas. If these machines are still sold as new, but already standing around a few years in their box, the rubber seals could become porous? However, this is not a "great problem" of ESAM6600 - but simply the ravages of time.
Our machine produces consistently good coffee and the many years. On 16.03.2010 we bought a new cover for the milk container since the cappuccino was no longer perfect. On 17.02.2011 we changed the brewing unit out to more than 5,000 cups of reference. That way, you can easily accomplish wonderful self, as opposed to all the other manufacturers with permanently installed units. In my opinion this is a big plus for DeLonghi. After our favorite button worked only sporadically to make coffee, I swapped on 13.01.2014 the operation board which I got cheap on the internet. According illustrated instructions for exchanging I found with the help of a well-known search engine. There are, incidentally, still the first seals in the engine and tightly.
To date, we attract a daily average of 6 - 8 cups of coffee or espresso (Cappuccino rare). We tried many different types of coffee through, even "Jamaica Blue Mountain" and "Hawaii Kona Extra Fancy" ('nice to have' but nothing for each day) - and ended up with "Espresso Sicilian kind, strong roasting" Tchibo. In addition, we have as the default settings on the grinder 4, and for the coffee brewing process "high temperature" and "very strong aroma" set. So we still tastes the best coffee ;-)
We can not confirm that the DeLonghi ESAM6600 prima donna would be unreliable or short-lived or of poor quality thus.
Well, now I drink a delicious first double espresso !!!