I didn't actually get to meet Markus, as it was a very 'hands off' smart apartments building, we checked in on a computer in the lobby and got into our room by ourselves.
At one point we had lost the keycard and i contacted smart apartments customer service. The person on the phone laughed at me and said 'well that's not goo' he wanted to get a security company involved but I told him we'd try somehow else without causing a fuss.
In the end we managed to wait for someone to leave the apartment and go into the lobby to use our QR code to generate a new card. To have this explained somewhere initially would have been great.
The room was alright, looked a bit more modern and cosy in the picture but it was mostly as advertised. The location was very close to an s-bahn station and a supermarket but it wasn't in a 'nice' or 'cool' part of town.
Good for a business stay, not so good if you want to go to berlin for a nice holiday