Kerem's apartment situated in the great location. It's very close to galata tower and restaurant nearby within few minutes walk. Also it's walkable distance to Sishane metro, istiklal street and Karakoy. The place is as shown in the photo, plenty of spaces for group or family. But I need to say that there are some defects on the floor or a little bit unneat on the bed. But overall it is clean and good enough for staying. The hot water is hot and the water flow is strong enough for taking bath in the winter.
The only cons is the master bedroom is locate close to the street, you may here people chatting in the restaurant close to the apartment as it close quite late at night. And also you may hear the prayer sound from the nearby mosque in the morning. But the other rooms is located at the back of the apartment so you may not find those sound annoying.
Anyway I would suggest to stay in this apartment if you visit Istanbul.