We were in Cesim's apartments for one week with our parents (6 people), That would be a very pleasant stay for us, in a great and nice location (a lot of nice shops and buildings, traditional restaurants, safe and lively atmosphere). Cesim was very helpful and hospitalised, He was available any time that we need his help or need something. He has a nice garden and restaurant which gives a spirited ambience to the building, I loved it.
Cesime's apartments are highly recommended for having an enjoyable stay with reasonable price in Istanbul.