It took many phone calls to get to be checked in, the first of which ended by being abruptly hung up by the person answering it. Even after all those phone calls I still had to wait quite a while by the property before I was let in.
I'm not too fussy but this house is not in tip-top condition, so to say. A couple of examples: The higher part of my room door had a gap wider than a centimetre. I received a brief visit of a little cockroach.
I was told that breakfast was complimentary, but I only found it laid out in the kitchen on one of the three mornings I was there. The other days there was a bit of butter and some orange juice among other things that seemed to have been lying there for a couple of days. There was no one making sure that the kitchen was kept clean, although I guess some guests may be partly to blame for that as well, if they didn't clean after themselves.
Other than that, the location was convenient for my plans. Train and U-Bahn were nearby as well as a supermarket. The public transport journeys to the places of interest in my agenda were short but overpriced. The distance to the Königswinter ferry was also walkable.