The apartment is very well-situated (2 min on foot to reach the U-bahn), quiet, clean, luminous and fully furnished (iron, hair-drier, etc.). Only downside was the adjustment of hot and cold water, it was either boiling or freezing, we did not manage to settle it.
The host Matteo is available, he answers very quickly and kindly and gives many detailed information.
We had a very nice stay in Berlin! Thank you!