Nice base for exploring central Istanbul. The flat is just the main shopping boulevard and near plenty of bars and restaurants. We enjoyed the little area with lots of antique shops.
The star of the flat is the panoramic window (in summer the roof terrace) with view on the Bosporus and Topkapi Palace. On one rainy afternoon we just watched the busy traffic on the water.
The flat caters easily for a few days. If you want to cook meals the supply of utensils is a bit basic but for staying a few days adequate. A nice touch is the free supply of drinking water. Heating did also work on chilly winter days. The flat is located in a quiet side street so no problems with sleeping.
Communication with Ali was smooth and pleasant. He welcomed us as planned and answered all our questions.
If you arrive at Ataturk airport you can take the metro easily. It is one change and takes one hour. There is a friendly Tourist Information at the airport if you need help figuring out how to buy tickets (not difficult).
Istanbul is a fascinating city and we'd be happy to stay in this flat again.