Without doubt a very positive experience.
The apartment is new and clean, and it has everything you need for a comfortable stay. All around it you can find many shops and places to eat, just by walking a few minutes. It's close to Beşiktaş Meydan, where you can take several buses to go to other areas of Istanbul; and also close to the ferry stations, which proved to be an effective and nice way to move around.
Cem is a wonderful host, very kind and accommodating.