The best thing about Mert´s place is its location. It is right in the heart of Kadikoy, with all its night life, restaurants and cafes, but just outside the hectic part, so your night rest is assured. Kadikoy is a great neighborhood to stay when visiting Istanbul, not only because its own great and authentic vibe but from here you can reach all other interesting, much more touristic places, like Sultanahmet, very easy and nicely with the ferry. From Mert´s place it is a nice 5 minute walk to the ferries and also to the bus station from where the bus to the international airport leaves (line 7).
Mert´s place is small, but it has everything you need. A small kitchen, a cozy sitting room, with a vinyl lp player!, good wifi. the two bedrooms are small but clean and the beds comfortable.
The apartment is located in an older building, so the amenities are also a bit old, but everything works and it is all fairly clean and fresh. It is not top-of-the-bill luxury, but the price asked for it makes it a great deal. The only thing I would suggest is that you bring a sleeping mask with you, as the apartment is very bright.
if you want a great location, a great value-for-money and a host who is very communicative, responsive and helpful, this is the place.