All in all the stay was great, but there were several details, that were not really convincing (the windows were really dirty, both of the toilet brushes were cheap- looking and had been used for a long time, the hooks for the towels were lose, ....). Furthermore, we had to buy water ourselves, not like it is described in the ad (water for free).
Regarding the comparatively high price for Istanbul- standards everything still seemed to be done without much love for the detail.