Steffen's apartment is awesome, the location is fantastic if you're wanting to get the feel of Kreutzberg. It's only a short walk from everything you might need, transport, shopping groceries, and places to eat, drink, and party are all right there. Despite this the apartment building itself has a really calm and quiet community feel to it, the neighbours are very friendly and the courtyard is shaded and cool throughout the day.
The flat itself is great, really nice big rooms with high ceilings. HUGE bathroom with bath and shower. The kitchen is fully featured and a really nice, light place to hangout and chill between trips around town.
Highly recommended, it was a superb base for our exploration of this mad and exciting city.