I highly recommend Karsten's apartment for anyone staying in Berlin! My husband and I recently went to Berlin on vacation and stayed at Karsten's apartment for 3 nights. We were looking to check in early in the morning (as we had an overnight flight and wanted to rest when we arrived at 10 am), and Karsten went out of his way to accommodate this for us. When we checked in, he greeted us and gave us great recommendations for fun neighborhoods/restaurants in Berlin. His apartment was clean, spacious, and looks as in pictures. The bed was also comfortable, and the blankets were warm. We were provided with everything we needed and no issues. Check-out was also very easy. I recommend his apartment for anyone looking to stay short-term/long-term.