My wife, my 9-month old son, my sister-in-law and myself stayed at the Conrad IST for 5 days/four nights last month on a award stay.
We were put in a large room at the top floor (16th IIRC), choice of lounge or restaurant for breakfast (which is on the floor below), great views of the Bosphorus, nice breakfast, very good choice of liquor in the evening and very tasty finger food available too. The food for dinner was actually so good (hot food, desserts, cheese, salad, etc...) that we actually never ate dinner outside that week. The staff were great and took great care of us during our stay even though it wasn't a paid one.
Would return there at the first opportunity.
Tell me if there is anything more you would like to know about this property.
UTA