Cozy apartment in a great part of Istanbul and Mehmet (Martin) is a great host. I can highly recommend this place.
About the location - Its in the centre of Kadikoy, a very vibrant part of Istanbul. You are 10 minutes walk from the main ferry terminal and bus station, getting to the European side is easy. There are lot of pubs, cafe and restaurants in the area as well as artisan shops and independent stores. Kadikoy is a great area for walking around and chilling with the locals, either in town or along the seafront. Fenerbahce football stadium is close by, maybe 15 minutes walk away.
About the apartment - It's a cozy place and has everything that one or two people would need. Considering the central location it was not noisy. Everything is provided and as described in the listing details. You do have to walk up 3 flights of communal stairs but they are clean and well lit. I did need fast internet for work reasons and the speeds through ethernet connection was around 90mbps - very fast.
About the host - Mehmet (English name, Martin) was very responsive to my questions, before booking and during my stay. He has excellent English and was always helpful.