Overall the place is great, in a beautiful old building in a fantastic location.
Jana is extremely helpful and quick to respond - for example, she got us a clothes drying rack at a day's notice because the one in the flat had gone missing. The self-check-in and check-out instructions were also very clearly explained.
The kitchen is well-equipped, even though some of the dishes and utensils needed a wash.
However, the flat being on the lower ground floor makes it dark and stuffy most of the time (we were isolating for 14 days, so it was probably worse for us). There was also a bit of an issue with hot water in the taps (this was mentioned in the instructions along with a quick fix, but it was still a somewhat frequent inconvenience).
In summary: For a long stay, the place is very well-equipped, but slightly depressing due to the semi-underground situation.