We had a wonderful time in Anna's flat in Mitte.
The flat is spacious, light and airy, and perfect for a small family or two couples sharing.
It has everything you need, including a well equipped kitchen, nice dining area, two large bedrooms and large bathroom with bath and shower, and amenities including dishwasher, washing machine, and iron.
The street is a peaceful street in central Mitte, you can walk to Museum Island and Unter den Linden in about 20 minutes. There are U-Bahn and S-Bahn stations a few minutes walk away.
The flat is kept very clean and there was a friendly cleaner who let us in when we arrived and gave us the keys.
I would definitely stay again if I go to Berlin.