Eugen’s apartment is great for travelling with a group. Right in the centre of Berlin with an s-bahn station across the road. Also many great restaurants and bars nearby. Eugen was quick to respond and he was extremely accommodating. The apartment layout is very good for groups.
One thing that you should be weary about is the door in the first bedroom that leads to another apartment, it can be quite noisy through there depending on who is staying in the other apartment, even though Eugen sets strict rules for noise.