Katja's apartment is bright, comfortable and beautifully decorated. It was perfect for my needs but stair adverse or heavily packed travelers should take heed, there are a lot of stairs to climb.
The neighborhood is a bit removed from the center of Berlin, dotted with cute eateries and very bike-able. To that end, Katja made a great recommendation for a bike rental service nearby.
Katja was communicative and friendly host. I had a lovely stay.