excellent single group head machine. Picky about coffee age, grind and tamp. Makes the best espresso I have ever tasted.
Positive Product Points
When you get the hang of this machine it will produce the best espresso ever tasted. The gradual raising of the lever arm is like watching ballet. Great for heavy use.
Negative Product Points
The size of the machine and the need for an external pressurized water source makes it difficult to use in any other situation but commercially or craftily. Extremely picky about grind since the lever provides less pressure then pump actuated machines.
Detailed Commentary
The machine I am familiar with is the Z9, lever action with one group head. There is no pump, so it requires a pressurized water line to run. It has a large single boiler. The machine itself is impressive and large. Since the coffee is brewed using a spring/piston system it supplies around 8-9 bar to the group head. This machine is built like a tank and is extremely simple on the inside. It requires roughly 15 minutes to warm up but is designed to be left on and used constantly. It could easily supply a small retail business with enough espresso to offer it to customers as long as it was not a coffee shop.
The machine was purchased off of ebay. When it was shipped it was in pieces and required reassembly. Some parts were lost in shipping (I assume) and the metric sizes proved troublesome.
Because of the lever action and the lack of pressure (at least in comparison to pump machines) the age of bean, grind and tamp are more important. We are constantly having to adjust our tamp to the age of the coffee. The single portafilter basket is far more forgiving then the double on this note. But it is not possible to get a ristretto pull out of the single basket. So learning the tamp for the double basket is well worth it.
Another note is that the steam wand and hot water dispenser work very well. The steam wand is a little hot, be careful not to scald the milk. Because of the size of the boiler one can easily move from steam to hot water to espresso pulling without waiting.
Buying Experience
ebay. Buyer beware.
Three Month Followup
Three months later and the Z9 is going strong. Roughly 2 months ago the seals in the piston/cylinder system gave out. The seal that gave out was the V gasket that kept water from coming up out of the group where the spring is. Unfortunately the leak didn't present itself very early and some rust developed on the spring. This is disappointing but seems to have not effected the strength or pliability of the spring. We obtained new seals and were successful in servicing the piston seals. The machine works better then ever.