My family and I were happy to stay in Willihy's apartment. In general, our stay was pleasant. The location is indeed great, being just a few minutes from Taksim Square, but located on a quiet street away from the noise of the crowded places nearby. Also, it takes around 15 minutes to walk down to Kabatas where ferries can take you through Bosphorus to the Asian side and other nearby ferry stations in the city. Just be ready that the area is very hilly, and you'll have to walk up on very steep roads.
Also, it's worth noticing that the apartment is quite aged, although well-maintained.
Last but not least, the host was super quick in responding to all our queries.