This is one of the best Airbnbs that I have stayed in. For one, it is a proper Airbnb - not a rental apartment filled with travellers. Pia and Lina made a real effort for me to feel welcome: on my first night, arriving late-ish in the evening they asked me to join them dinner, after which we sat and chatted. They were both super friendly and available to offer advice about the neighbourhood and just chat generally. Bav too was awesome in the run-up to my trip, sending me loads of stuff on slightly different things to do in Berlin, recommending cheap bike hire places etc.
The room is exactly as advertised: clean and bright with a funky mezzanine bed. Lovely big bathroom as well. The apartment is right by Hermannplatz U-Bahn stop which makes it convenient to get pretty much anywhere in the city. Not that you need to take the train: it's a really lovely 40 minute walk into the city centre - the best way to explore Berlin.
So in sum: a really fantastic listing, if you get the chance don't hesitate to stay here. It'll certainly be my first choice when I return to Berlin!