Now something positive:
1. The egg cooker is seen in design an outstanding success. The stainless steel hob is easy to clean. However, that should be done after every cooking process, as this may remain lime residues and these are then difficult to clean. But depends also on the hardness of the water.
2. The hardness setting works very well. There were only 2 trials needed that to make the eggs as you have imagined it. The position of firmness adjustment is easier to remember and adjust well.
Conclusion:
I'd 'Rommelsbacher HE 400 egg boiler' Buy again at any time. The price / performance ratio is okay. If the manufacturer, the above two negative points have to get to grips with yet, so that's a good device!