Our family stayed for 6 months in Marine's lovely apartment. The welcome was warm and the place was as advertised. It was very easy to communicate with Marine as she speaks fluent English and is very quick to respond. Marine quickly helped us get started in Berlin, both in the apartment and in Berlin (with her tips), and questions that popped up later where quickly answered through instant messages. In the rare case that something needed maintenance, Marine came to fix it the very same day. She was also very accommodating when we wanted to extend our stay with a few months.
The apartment is very nice and cosy. It is a spacious traditional 1-bedroom "Alt Bau" with high ceilings, wooden floors, double glass windows decorated in a 70s - 80s style that made us feel right at home. The apartment has great storage capacity, with plenty of closets and cabinets as well as shelves in the living room and a storage area in the hallway. The kitchen and bathroom are well equipped and our daughter loved taking baths in the tub. There are plenty of windows which makes the place light and well ventilated.
The building itself is very traditional Berlin style. There is place to store bikes in the indoor yard and strollers near the stairway. There is no elevator but the stairs are comfortable to climb and we didn't have any problems. There is a bakery on the ground floor of the apartment which is such an asset: they sell coffee, bread, some basic groceries in case you run out or don't want to walk to the supermarket and as a bonus they also receive your packages when you're not home (extra bonus: open on Sunday and holidays). There was always plenty of parking space in the area when we needed it (visitors).
The location of the apartment is terrific. Very close to the Mauerpark and literally tons of shops, restaurants and parks around. There are at least 7 supermarkets within 10 minutes of walking, 2 shopping malls, as well as three S-Bahn stations (Schonhauser Allee, Bornholmer Strasse and Gesundbrunnen) and two U-Bahn stations (U2 Schonhauser Allee and U8 Gesundbrunnen). If you have kids, the experience in and around Prenzlauerberg is fantastic: the density of playground in the area is unrivalled with 5+ playgrounds all within 5 minutes of walking, including two with water fountains for the warmer summer months. We also loved the animal farm nearby, which was a daily trip for us and our daughter. The apartment itself is also safe and child-friendly, with a high-chair and travel bed.
We couldn't have wished for a better place to land in Berlin and our stay at Marine's place was everything we hoped for and more. Highly recommended!