If you are going to Istanbul you can stop searching for places to stay now, I'm sure Metin is the best host you will find and his apartment is really great!
The apartment is gorgeous and it is on a nice neighbourhood. You will find a little market where you can buy the essencials in 3 minutes walking, If you is like us and prefer the public transportation over taxis you are just a few walking minutes (800m) from the subway station.
Metin is a really an aswesome person, you are going to became friends and he will do anything to help you if you need. He even helped us (actually he did it by himself) to order pizza online because everything was in turkish, and always kept in touch in the case if we need anything.
We for sure recommend you to stay here, this stay overcame our expectations!