Apostolos was very helpful for my trip to Berlin. It was my first time visiting the city and he gave really detailed instructions on how to get there and met me to give me the keys and show me around.
The apartment is perfect for a single person or a couple (I was there 5 night on my own and then my boyfriend came for the weekend). It has nice high ceilings and is a good size. It is also in a great location, very near a lot of restaurants, bars and cafes. I would highly recommend.