Mustafa's place is amazing, it is close to Sultanahmet metro as well as markets and restaurants, the room was huge and the amenities were top notch.
Mustafa makes everything very organized and was more than generous to give me a discount. I would recommend everyone to choose this hostel as you get private rooms but with other amenities which you could never find in any hotel.
Lastly, thanks Mustafa for your hospitality, it is nice knowing you personally as a human being.