Staying with Ece and Guneş was the best! I honestly can't think of another airbnb stay that has been better than my stay with them. They were so welcoming and flexible. They would often invite me to talk with them and their friends as well as give me recommendations for places to visit and things to do in the neighborhood. They were even so kind as to make a Turkish breakfast for me! I definitely feel like I've made friends for life and feel really really lucky to have stayed with them.
In terms of the apartment, the layout of the apartment is super sweet, unique, and full of detail. It's also the perfect location if you're hoping to explore Kadikoy and have easy access to the European side. The ferry and metro are just a 10 minute walk away (buses are about 5 minutes away).
I highly recommend that you stay with them. You're guaranteed to have a wonderful time in Istanbul!