Overall we had a lovely stay. There is nice light and the bed is cozy with nice linens.
The apartment needs some updating and some of the furniture is a bit worn/uncomfortable.
For Berlin, the flat is expensive (as per our friends)-- but perhaps this is misinformation. Nevertheless, it's worth making more comparisons.
The balcony is small but lovely, if the weather permits.
There is one flight up from elevator to the flat. Helpful to know.
A few extra touches of nice soap and soft towels/robe, would add a lot.
Christoph is easy and reliable and no nonsense, which we appreciate. I wish there had been more details related to how the apartment worked (heat/dryer/etc).
The neighborhood is peaceful and just a few blocks from the metro and a nice square for shopping or coffee.
Hope this is helpful.