This was a lovely space! It's cute/stylish, comfy, very clean, and in a quiet neighborhood while also being very centrally located and close to public transit. The apartment had everything we needed (including a french press and espresso maker!). It was actually bigger than I thought it might be based on the pictures! There's plenty of restaurants within walking distance, as well as a drug store and a grocery store.
Karsten was a great host. He was easy to communicate with and replied promptly. We had numerous flight delays and so had to keep pushing back our check in time, but Karsten was very understanding and accommodating. He even offered to help us out when the airline lost our luggage!
I would definitely stay here again the next time I come to Berlin!