The host, Alexis, was very nice, he met us in person and let us in the apartment, gave us a tour and was always available. We had a very easy time getting in touch with him on Whatsapp, and he brought in some extra cookware we asked for. We arrived late in the evening, but he came and let us in. His initial welcome email also had a lot of helpful information, nice places to visit, along with a paragraph in Turkish to show taxi drivers to easily locate the apartment, which came to our help.
The apartment is very close and in walking distance to Taksim square, has a lot of small shops and restaurants and cafes around it, and is in a quiet building and street.
The apartment also is nicely ventilated with two ACs, has a nice view to the street, and is very clean. All appliances and cookware were included and the host considered even small things, like including several dishwashing tablets, detergent, trash bags, extra soap, a hairdryer and iron, among other things.
this place was also very nicely decorated. The beds (and the bunk beds) are comfortable and the rooms are spacious.
I can't say enough about this place! If you're visiting istanbul, do yourself a favor and book this apartment :)