Martin's studio apartment is a place I can only recommend. It is cosy, spacious, well-connected to S-bahn and U-bahn stations, offers a bakery and Döner near by, along with Lidl supermarket. Martin himself is really funny and oriented us well to the layout of Berlin. Communication was super easy and quick. He even went out of the way to bring us travel tickets that we had forgotten to print. Wonderful host!