The apartment is in a prime location. less than 5 minutes away from the Taksim square and Istiklal street. Good location and a well done apartment. The host answered all my questions very promptly and is very friendly. We arrived at 1 am and Cengizhan and his girlfriend were very nice and waited outside the apartment to greet us.
The apartment is in the area where there are steep walks, so when going down to get tram, the walk up to the apartment is quite steep and maybe not much suitable for elderly people or people with the knee problems. We managed to do it daily though (with a struggle).
There is a supermarket right at the doorstep, with many restaurants around the corner. It is noisy at night times due to its central location and the disco's nearby. Most of the nights we had some trouble sleeping.
In summary, I would recommend this apartment.