We were a group of 6 girls, and the size of the apartment was perfect for us. Since the weather was so nice, the terrace also came in good use. The only negative thing with the apartment was the heat when we were sleeping. This could be fixed by installing a real air conditioner (and not just having a fan).
The neighborhood was super cozy. Prenzlauer Berg was rich with cafes, restaurants, bars and stores. We had a really good time here.