Josef's place is a great place to stay in Berlin for 2-4 people! It is a short walk from the Frankfurter Tor Ubahn station (5-10mins) and the layout is pretty much just like what you see on the pictures - the apartment was very clean.
We were greeted by Veronika, who was very hospitable and she and Josef were helpful and communicative. The only issue was with the wifi, which we connected to, but weirdly got no internet out of. Hopefully Josef will take care of this issue, otherwise it was pretty much perfect!