We had a very pleasant stay at Sertaç’s hotel.
The location is excellent - behind Blue Mosque, in Sultan Ahmet - 5 minute walk to the mosque. Close to the touristic attraction from the old part of Istanbul and from Bosphorus. Public transportation nearby.
Sertac and his brother have been very friendly and helpful. Gave us a lot of useful tips.
The room was nice and clean. Basic room. There is a railway behind the hotel, but we slept with the window closed and it didn't bother us.
The only minus is the breakfast, which wasn't very good or rich in options. Same food every morning. But nearby there are lots of delicious and affordable places to eat.
Good value for the money. I recommend it.