We stayed at Carsten's apartment in Berlin for 3 nights, it was lovely, clean and in a good location - walking distance to/from Berlin Sudkruez station. The only con is that the apartment is on the top floor... you have to climb all 111 steps to get to the apartment. I was 5.5 months pregnant at the time of stay - it was good exercise climbing those steps but I definitely needed to rest halfway. Just be aware if stairs aren't your friend. The apartment provided everything we might need except for toiletries like shampoo, soap etc. There is a washer and a clothes line which is convenient if you needed it like we did, however, no washing liquid/powder is provided... but you can purchase one relatively cheap in the nearby stores. Overall, great experience at this place.