The apartment itself is great and is located really in a central area. The host was kind and communicative all the time, being polite and always up to give good infos about the city and its attractions. There are two down sides: Wifi connection was really poor and sometimes even not working once we were in the apartment, and in the bathroom the shower hanger not existed at all, so we had to take a shower holding it.
To sum up, we recommend the location and the host. Enjoy Istanbul!