We had a nice stay at Ozde And Omer's appartment. The location was in close proximity to the airport shuttle bus stop at Taksim, just a short walk from Taxim Square. Walking distance to bus/metro/tram - or just use those legs to get yourself down through the busy street of Istiklal. Lots of shops, restaurants, hamams etc close by. Do expect some noice as the appartment is placed just next to Tarlabaşı Blv. which is quite busy both day and night, but that's what you get for staying "close to everything" in Istanbul.
Our host responded quickly when we had questions regarding the best way to get from the airport to the city on our arrival to Istanbul, and luckily was able to arranged for our checkin in the middel of the night since our flight was delayed several hours. The appartment is newly renovated and looks smashing, with 3 large bedrooms to host 5 people, a decent sized bathroom, kitchen with dining area and a small livingroom.