I recommend 100% Maria Antonia’ s place. We have felt like at home during our stay in Berlin. The room was big, superclean and the bed very very confortable.
The location is perfect just 10 min walking from Alexanderplatz and there is a U station just next to the house.
The communication with Maria Antonia was very easy from the moment we did the reservation, she replied to all my messages in a few minutes so for sure you will not have any problem arriving there.
I would repeat again without any doubt.