Everything was good and the apartment was the same as in the pictures. It is a separate apartment on the 2nd floor, super close to Istiklal street. A great thing for Cenk, that we said we are cold and he turned on the central heating for us. Also, it was very pleasant that he met us personally and showed the apartment.
The only cone is that there weren't bathroom suppliers, but the liquid hand soap.
But its not a big deal and if I come to Istanbul with a company again - we'll definitely choose Cenk's apartment.