I can recommend a stay at Orhan's place to everyone. He is a great host, very helpful and makes you feel at home. He picked me up from bus station and also assisted me to the bus to the airport on my way back which was a huge help.(Thanks again Orhan!) Don't hesitate to ask for recommendations on what to see in the city or any other 'tourist' thing.
Apartment is right in the center of the best district of Istanbul- you can find everything what you need here, restaurants, pubs, clubs and more. It's super close to ferry stations that will take you to the European side of the city, metro station or a bus station. If I go back to Istanbul I'll for sure book my stay again at Orhan's. :)