Andreas's place was fantastic. I stayed with a group of five, and though it was a bit cramped, Andreas went out of his way to make us comfortable. The flat itself is really comfortable and cozy. While it's in a bit of a sleepy area, it's extremely connected to public transportation and actually in a cool part of Berlin to see, and while I was initially skeptical of the location, it ended up being super confident to explore Kreuzberg and the rest of the city. Would recommend to anyone.