My stay at Klaus' apartment was fantastic. The location is perfect with the ability to get anywhere in Berlin within half an hour via S-Bahn or U-Bahn stations right outside the apartment. Within a 10-15 minute walk there are tons of restaurants, shops and bars where you can check out various neighborhoods quite easily.
Klaus went above and beyond to make my stay both comfortable and enjoyable. The room is spacious and clean, with space in the kitchen as well for cooking and storing items from the supermarket. Klaus himself is a very kind and interesting person who is always willing to help provide tips or advice on the city. I enjoyed greatly the chance to get to know him a bit, and had a truly nice experience at his flat. I highly recommend Klaus, and would definitely stay here again!