Jürgen is a great host - he accepted us in the late evening (around 11 pm) without any concerns, and provided us with useful touristic information, as well as information regarding the house. We have not encountered any issues during our 5-days stay - everything was fine.
House itself is big enough for 3-4 people, clean and cozy, located in quiet area of Berlin. Bus stop is in 15-20 minutes of walk from house, so it would not be an issue to get to the Berlin center.