My wife and I bought this machine soon after getting married as a house gift to ourselves. We both liked coffee and espresso and thought it would be neat to have the machine. Though it does not produce the same taste in coffee as is available from a coffee house, we learned to enjoy the flavor.
This is a steam-powered machine. Meaning, a boiler heats up a tank enough to cause steam. As the pressure builds from the steam, the water is forced out of the tank, through the ground coffee and into the '4cup' carafe. Water is placed into the tank by a screw cap on the top. The portafilter has a loose filter basket that will hold an amazing 4tablespoons of coffee. The housing of the machine is plastic with the only metal really visible is on the filter and filter holder and the steam wand.
To operate the machine that I have, a 3-position lever is located on the top left with settings for off, steam, and brew. When the lever is turned to brew, the boiler begins to heat up the water in the tank and the steam pressure begins to build. After enough pressure is produced, the water begins to get forced through the coffee. The boiler continues to heat up and after an ounce of brewed coffee is in the carafe, this is the indicated level that the boiler has heated up enough to begin steaming.
Throwing the lever from the brew setting to the steam setting causes a valve to close and the built up steam to is fed through the steam wand. An adapter to the steam wand is supplied with the machine but is difficult to keep clean and only moderately helps with foam production. You can steam as long as there is enough water in the tank. It must be said that a significant amount of the water is used for steaming and Krups recommend an extra ounce of water added to the tank for the purpose of steaming. I've used more than that to steam 12ounces to a decent temp. Steam pressure is decent but wet and inconsistent.
Shot extraction times, crema, color, tamp pressure, grind size, none of it was in my vocabulary when I bought this machine. Now that they are, I can tell you that with this thing they will not matter much. Your coffee will always be scorched and not have any of the delicate nuances you can expect to notice from brewing with a pump. The dark coffee you get is not all that unpleasant when used in milk-based drinks but don't expect much.
Its astounding that this thing has lasted so long. We have used it several times a week without any problems. Nothing out of the ordinary was done but an occasional deep cleaning.