We had the pleasure to stay here with a small group of friends/couples, and did really enjoy our stay. Some reviews mention the presence of sex workers in the surroundings, but it should really be mentioned that the building's entrance is literally meters away from the U-Bahn exit, so even at very late hours you can get home without even seeing one - we always walked home from Nollendorfplatz neighbourhood (10-15 minutes) and had absolutely no problem.
We had both flats for ourselves, with plenty of space. Several coffee addresses close by offer nice breakfast options (e.g. Einstein Café, or Queen of Muffins), and some supplies in the flat offered the early birds a first pre-breakfast.
Chilling in the flats was really nice, but I would probably not count to cook a very large meal for several people.
Communication both through AirBnB as well as for check-in details went very smoothly, in spite of our late flight arrival.
For getting around, two U-Bahn stations are nearby, Kurfürstenstraße just by the door, Bülowstraße 5 minutes away but with different connections (e.g. directly to Alexanderplatz)