My family had a fantastic stay at Halil's place. The four of us just loved it! Halil is a great host, super responsive and very helpful. The condo is situated in an upscale complex. There is a free shuttle the goes almost every hour, and it will take you to the Kadikoy ferry station, from where you can catch a ferry to the old town.
The whole complex is a very beautiful with somewhat futuristic architecture.
Halil's place is clean and well equipped with everything you might need for a comfortable stay. There are two bedrooms and two bathrooms, with two queen beds. One bed has a softer and the other one a normal/harder mattress, which is important if you have a bad back, like me, and you need a bed that is not too soft.
There is a fancy mall nearby, which also has a very big grocery story in the lower level. Adjacent to the mall there is a Metro station (Unalan).
You will not make a mistake if you book Halil's place. Highly recommending!