The location of the apartment is great in Prenzlauer Berg. UBahn just around the corner, as well as grocery shop and restaurants. If you come by car there is also cheap option to park for 5€ a day in Arcaden.
The apartment is perfect for 4 people. But the rooms are quite dark also during the day, because it is in the ground floor and the windows look towards the enclosed courtyard. All in all, good stay aftrr exploring Berlin the whole day.