This is the place to stay in Berlin.
Claudia is very kind and her baby is too adorable. But if you're worried about the baby, they live on one side of the apartment and the rooms for rent are all on the opposite side (the apartment is rather large).
The apartment is very clean and each room has an awesome decor matching it's name. It's like a proper hotel.
The area around the apartment is full of great eateries.
And Alexanderplatz is an easy walk or just two stops away from the apartment.
Exploring the area is wonderful, but my gf and I spent some time just admiring the apartment haha.
If you use the map of the area that Claudia shows you during the introduction, you'll have a great time.