William's place is a gem. If you're wanting to stay on the European side, you can't really do better in terms of location: stone's throw from Istiklal, Cukurcuma, and Cihangir. The view from the terrace is one of the best I've seen in my two and half years in Istanbul and the easy access makes it seem like it's part of the apartment. Best part for me was the library William offers with every type of history (including Istanbul and Turkey) and a fantastic taste in fiction. Highly recommend!