The apartment was very good and well-situated: it was just some 10-15 minutes from the Tegel Airport, 20 minutes walk from the Charlottenburg palace. The apartment is 100 m from the U-Bahn and S-bahn stations, which was very convenient since we were travelling a lot within the city and outside (the ZOB is couple of stations from the apartment).
Anton was not able to meet us in person; however, a housekeeper Ms Wydmuch was very helpful and nice. Since we were arriving on the 1st of January when all grocery stores are closed, she described us where we can find some food etc (btw: the best store nearby is Rewe).
We would definitely recommend the apartment for those who like cosy and quite places to stay and for those who wants to have good transport connections not only within the downtown.