It was an amazing experience!
Hakan's is a perfect host - starting with my arrival which was flawless till my departure which was also worry free. He made sure I feel comfortable and safe at his place, was respectful and polite, very knowledgeable person and a good listener, too. The apartment is perfectly located and easily accessible by Marmaray, in a very quite and peaceful neighborhood with cozy cafes around the corner. Hakan keeps it very clean and tidy, you can also find lots of books (if you're Turkish native you're lucky).
I really enjoyed my stay. Hakan, thanks ones again!