İlkay and his colleagues were absolutely fantastic and accommodating. They helped me with all my questions and even met me after 2am for my check-in!
The apartment is perfect for a solo traveller or a couple, though there's a pullout couch in the living room, so it could accommodate additional travellers. It was also very clean and furnished with all necessities. But the absolute best quality is its location. It is literally steps (less than 50 meters) from Galata Tower! The streets around Galata Tower are filled with cafes and restaurants and plenty of nightlife. In addition, it's walking distance to Taksim Square, Galata Port, Karakoy Port, and Eminonu. You can take cheap ferries from there to anywhere.
I highly recommend this apartment as a hard to beat place to stay in Istanbul for its location and value!