Jan was a really nice host. The apartment is wonderful, especially the living-room that is spacious and has a great couch with a large cable TV in front. It was very clean and in very good shape.
The neighborhood is lively, full of restaurants, coffee-shops and grocery stores, nevertheless, it has a very quiet and local atmosphere. It is close to Schoss Charlottemburg, so if you like jogging it has a fantastic park around. It is about 15 minutes away from the tourist attractions by public transportation, however, you are not "right there", a fact that for me was simply great. There is a Bio-bakery just downstairs, so you wake-up to the smell of fresh bread!
I highly recommend Jan's place in Berlin!