If you are coming to Istanbul to visit some of its must-visit-places, then this is the best place to stay at. Amazing location, located exactly behind Hagia Sophia and sharing the same wall with Topkapi Palace. It's located in one of a historical and famous street in Sultanahmet called Soğukçeşme (you even can find it in Wikipedia). A very decent and safe neighborhood. 24/7 there will be polices and security guards in the neighborhood, given that it is in the museum, historical and touristic area. We were given the bigger room with no extra charge. You definitely can explore Sultanahmet area (Blue Mosque, Hagia Sophia, Topkapi Palace, Gulhane Park, Basilica Cistern, etc) simply by walking, even it's closer than the famous hotel you can find in the area. We (me and wife) loved this place so much! We stayed there comfortably. Highly recommended. Metin was a very kind and good host. Communication was quick and simple. He helped us a lot, such as providing and fixing an electricity plug converter, lent us a temporary simcard, and also his nephew who happened to work in the cafe besides the place was really helpful.
Please note, that Sogukcesme street is only for pedestrian most of the time. I think its only at late night up to early morning, cars are allowed to pass. Also, you need to climb up to the house a little bit through the stairs (from the entrance of the house), which was just one floor up. So with these, if you have a lot and big luggages, you might want to consider this. We personally had quite big luggages with us, it wasn't that big deal, since it just happened once during the checkin and Haroon (Metin's nephew) and Metin himself helped us carrying the luggages up to our room.
At night, we did hear some music played from the cafe next to the house like what other reviewers said, but it was not a disturbance to us at all.
Overall, fantastic place and host! We loved it and will definitely be back.