The apartment is exactly as advertised and pictured in the images; clean and with more than enough space for one person (as it was in my case), and good quality for the money especially considering prices in Zurich.
Luck was not on my side as I stayed there during some restructuration work on the external part of the roof of the building (the apartment is on the very last floor), so there was some noise and inconvenience, but this was clearly outside of Niels' control, who on the other side has been very quick in communicating with me (and with the building owner) to make sure that those external factors were not interfering too much with my stay.

Overall a place I'd suggest for anyone looking for a nice and affordable apartment, especially if like me you're going to enjoy its convenient location (I could walk in <10mins to my destination).