Altug’s apartment is in a great location, and the balcony has a great view over the rooftops and the Bosphorus. My friend and I stayed there for a week and we spent most of our time in the apartment out on that balcony. We were mostly out in the neighborhood and the city though - the neighborhood around the place is great.
Altug and his colleague are also very responsive and helpful with setting up taxis, answering questions, etc - they run a hostel across the street so it is easy to check in with them with any questions.
One note is that the apartment is fairly bare-bones inside - it was fine for our purposes, but if you’re traveling with kids or looking for somewhere to relax inside after a day out in the city, you might want to find somewhere with slightly higher-end furniture/comforts/etc.
Overall, we had a great stay!