All three are single boilers, so there will be wait time between
brewing and steaming.
All three are e61 group machines
The Unica and Classika have coated steel frames, the Alexia Evo has
The Alexia and Unica have a three liter water tank. The Classika is
a little smaller at 2.8 liters.
The Alexia has a 1400 watt heating element, the Unica 1300, and the
Classika 1200. More watts mean faster warm up time and better
The Alexia has the largest boiler at .75 liters. The Unica and
Classika both have .5 liter boilers. Smaller size means greater
chance of running out of steam pressure, etc.
The Alexia has a hinged water reservoir cover that makes removal or
filling of the reservoir easier. The Classika and Unica have a cup
warming tray that has to be removed before you an access the
reservoir. This can be inconvenient if you have cups on the warmer,
The Alexia and Unica have copper boilers. The Classika has stainless
steel. Stainless steel is less susceptible to limescale build up,
but copper provides better thermal stability.
The Classika and Alexia have insulated boilers. The Unica does not.
Insulated is better for temperature stability and can make the internal components last longer due to less
exposure to continuos heat. It also reduces the temperature to touch of the
external of the machine if you have boiler insulation.