The other reviews have covered the potential pitfalls pretty clearly - it’s a fourth floor walk up, and there is no lock on the bathroom door. I stayed in the “orange room” (I assume they rent out other rooms, hence the need for clarification). It was right next to the kitchen, and the walls are thin, and also opens onto the street, so it was never quiet - not a dealbreaker, but something to be aware of.
The place is spacious, beautiful, and homey. It is very clearly a home, and has been for many years. Gudrun and her daughter were very warm and friendly, and communication was not a problem at all. I came and went as I pleased with no issues.
The thing that I would want to make clear to future visitors is the bathroom. It’s incredibly odd to me they haven’t put in a lock - I have the same door at home and it took me about 15 minutes to install one myself, so the “it’s an old house” explanation was strange. I also live with 4 roommates at home and have never had such a problem finding the (single) bathroom unoccupied. One of the days, I missed a city tour because someone was in there for over 45 minutes. While I totally understand how difficult it is to time your day with 4+ people staying in a flat with a single bathroom, this was more than a mild inconvenience. Just something to note for future visitors - if you’re an early or late riser, I don’t anticipate this being an issue.