I had stayed at one of Martin‘s flats in this house a few years ago, before it was on Airbnb. I‘m happy to say it was as comfortable as I remembered - clean, well equipped (ours was a longer stay, so we appreciated the washing machine), and in a great location: The M41 bus stops outside, and that gets you to Potsdamer Platz, Hauptbahnhof or Hallesches Tor, where you can change to the U6.
I remember that during my last stay, the WiFi signal was quite weak, but that appears to have been fixed and we had no problems with it. Communication with Martin was easy, swift and friendly, and I‘d recommend it if you are looking for somewhere clean and comfy, in a good location.