We were 5 people (2 adults and 3 teenagers) and we spent for 4 nights into Ilona's apartment. The apartment was clean and the handover of the keys was very fast and efficient.
The apartment is located on the top floor and is very quiet. There is a metro station in front of the entrance of the building and a supermarket in the street. Main attractions in the City Center are at 30 min walks from the apartment (very nice walk along a canal).
We had a late flight on the last day and Ilona was really flexible and arranged for us a place for our luggages so that we could enjoy Berlin till the last minute. This was really appreciated!
We had a very nice time in Berlin and I highly recommend the apartment for people who want to discover Berlin and its fabulous and rich history.