We stayed with 3 adults and a baby at the apartment and we had a great stay at Flo's apartment. It is at a good location, close enough to Berlin city center and easy for transport options. Parking is free and tram and train station within 3 minute walking distance. The apartment is very new and is spacious (especially the bedrooms) and well equipped. Also the bathroom is very comfortable and clean. At the entrance you have to climb a small stairs (8 step) to get to the elevator, for us no problem, but something to take into account when this might be difficult for you.
Communication with Flo was fast and easy. He responded very quickly to my messages and shared extra information on the topics I requested.
This is a great place to stay when visiting Berlin and surroundings.