Our stay at Ali's place was amazing.
The apartment was excellent, very clean, not very big but very good organized (it was 3 of us but wouldn't make a difference if it was 4), fairly big and very clean bathroom and the location is 5 minutes of walk away from Sultanahmet Square, Hagia Sophia and The Blue Mosque (one of the best if not the best location in the city).
Ali was such a great host, very helpful and polite. For everything we needed he was there in a short time and he provided us with every possible information.
Also as a bonus Ali owns a shop only few houses away from the apartment and you can buy groceries you need there.