I've just come back from Istanbul, where I stayed at the Blue Tuana Hotel. It turned out to be a great choice. We booked a twin bedroom, but upon arrival we were given a bedroom with a double+ twin beds. This leaves not much spaces to move around, but since we were 2 people it was OK. We stayed in room 503 and the view was on Marmara Sea. Imagine how amazing!
Hotel: It is a small family- owned and run hotel. Everyone who works there is a stakeholder, from the house keeping to the manager. This makes things a little slow, since there isn't much staff, but you can guarantee dedication& care about customer satisfaction. I would say the price is very reasonable.
Location: Located in Sultan Ahmet, close to Hagia Sophia, Top Kapi and the Blue Mosque. All within 7-10 min walking distance. Arasta Bazaar is less than 5 min away. Sultan Ahmet tram station is less than 10 min away. The hotel is located in an old district. Stone streets. Small alleys. Amazing façades. Many routes to explore.
View: One side of the hotel overlooks the Marmara Sea, the other Hagia Sophia. The roof restaurant offers both views and leaves one with a dreamy fairy tale like state.
Cleanliness: Can be improved. Towels were changed daily, but twice with ones that had stains. They were clearly washed but needed more care. Bed sheets weren't changed. But I am sure they would have been changed them had we asked. Over all, we can say it is a clean hotel.
Staff: Very helpful, very friendly!