Overall, we had a positive experience of staying at this apartment. It is a very comfy and well-decorated place and is more spacious than we expected. The flat can comfortably accommodate 3-4 adults. It is within a walking distance to the central railway station and other places of attraction.
Please, note that there is a broad road with busy traffic just in front of the building, but this does not cause significant problems with stillness. Overall, it is reasonably quiet in the apartment if the neighbours do not make any noise (but sometimes they do).
There were a few issues with the cleanness of the place. In particular, there are some stains on the walls and furniture. Also, the sofa in the common room has to be repaired. If this is fixed, the place is goo​d for a stay in Zurich.