We went to Berlin with 3 teenages. The apartment was nice and clean, and it was enough beds for every one. What we appreciated the most was to be welcomed personally when we arrived even though we arrived almost at midnight. It was also someone available by phone or in nearby during our stay, so we got information right away when we had any questions. The apartment was centrally sited, as it was walking distance to Alexander platz, Museums Insel, nice restaurants etc. It was only two minutes walking distance to U-bahn. Due to very warm summer days, we had to open the windows at night although fans were installed in all rooms. We did then experience that it was very noisy due to traffic all night, but if you are sleepy enough you may sleep through the noise anyway.