It was a mixed experience also clouded by our suitcases not arriving at the airport and the first 3 days with a lot of rain.
At first the apartment is nice. Nice colors and the basic things you need are there. The photo's are giving a better/bigger impression than the reality, but no problem. The shower/toilet is a combi and very small, which makes that everything gets wet when using the shower. But also not a big problem. Sometimes there is no water pressure in this part of Istanbul, but this can not be influenced by the owner. A thing i didn't like about this apartment is that there is a sitting corner directly before the apartments door, which can be used by anyone. It is an old building and if people are sitting there (late in evening or early morning) it is if they are sitting in your apartment. The shared terrace is wonderful and the view wonderful. The location is also a mixed thing. On one side it is a very special neighborhood, where tourist normally will not come very often. That makes it an unique experience. Some part's are better and other worse in there looks, old and dirty or characteristic. It is an very traditional area where most women are wearing Burkas, but we had no negative experience, but they are not open tourists either. From the River or the main street of the neighborhood the streets are steep up or down. Furthermore is the apartment mostly just a little far from the sights you want to go if you want to walk al of it. The taxi's as described in the mail from the owner are not as cheap as they say, the bus ticketing is difficult to understand. Metro was the best experience we had. A big problem is the language, people in the neighborhood are mostly not or just a few words speaking English, signs are mostly in Turkish. The same problem is in the apartment. Mustafa is very helpful but it is difficult to communicate with him. A little italian and even less English doesn't make it easy. And although he is very helpful, if things not going his way or he is just awake then there a some ruff edge's coming up. All in all i would recommend this place only to fit and experienced travellers who are not looking for a perfect experience and are used to improvise. The non tourist area and the beautiful terrace compensate a lot if your into that.