The apartment (room actually) is in the Kreuzberg area of Berlin, for us it was important as we were visiting friends who stay nearby.
The house was easy to find, the check-in process is easy and described in detail.
The room is not huge but it is fair. It's a bit weirs that it is on the ground floor and without the drapes people can see right in, but didn't bother us as we we came in fairly late anyhow.
Communication was very good as well, before and during the stay.