I would never go there because I would never find that place as it is not on a tourist area.
My friend who is from Istanbul recommended it and I went there. The Sis was excellent. Simply the best I ever had. I wanted more and more. Also many locals seem to go there so I assume the quality is good. Seems that the owner has been in a TV show and the service was friendly. Prices are more than ok. I recommend to any tourist that wants to eat proper Turkish food.