Quite good and the eggs come out very well boiled. If any break, it will be one or two and that depends on the batch and where you get them from.
The amount of water varies from egg to egg and of course the time.
The only thing is that they haven't come out soft-boiled and they come out somewhere in between with a half-filled measuring cup if there are 5 eggs inside.
Usually I boil 3-4 eggs with a little more water than I put and the time it takes is 12-13 minutes for the process to finish. The egg holder after washing and drying and the device after operation release salts (depending on the water) that you pour into a bowl of vinegar (the known one) and you put the holder/lid inside and in the device you pour the vinegar like water and leave it for a while or as soon as they multiply and clean immediately wipe to avoid whitening.
P.S. There are several ways to clean the residues they leave in the device.