We stayed at Dirk’s for a complete month. The apartment is perfect for long Term stays, the kitchen has everything you need to prepare homemade food. The heating works perfectly and the balcony is great! There is space for parking bikes and the location is very convenient, just a few metres from the Hohenzollern ubhan and the 216 direct to the Zoologicgarten station stops literally in front of the flat.
The Ku’damm is a few blocks away and there you can find all sort of shopping stores and plenty of restaurants.
I would definitely recommend it!