We had a great stay here! It is a great location and very easy walk to many of the top tourist sites and restaurants. The beds were comfortable and our hosts (and their friends who helped) were very helpful and communicative. Highly recommend for those who want to see the old part of Istanbul easily.
Layout information--it is a ground floor apartment and has about 3 steps up to it from the outside. From entering, if you turn right, you'll reach the living space with a table that seats 6, tv, and sofa. Off the living space is a bedroom with 2 single beds and a larger bed. Plus a wardrobe. From the entrance, if you turn left, you'll reach the kitchen (small, but manages to fit a lot), small bathroom, larger bathroom, and 2 bedrooms. One bedroom has a large bed, dresser, and wardrobe. The other bedroom has 2 large beds, dresser, and wardrobe. Both have balcony access.
Walking from the apartment everywhere is very convenient. A note on driving--this is the old part of Istanbul and streets are very narrow, often steep, with tight turns and cars parked everywhere. Many streets are 2 way but only the width of one car, so it becomes a bit of a battle to get the correct way and may involve backing up. We arrived in a travel agent shuttle and he made some wrong turns, got lost, and it took forever to get back to where we needed to be. He had a hard time making some of the turns. This was early afternoon on a Tuesday. My husband arrived in our car about 8:30 am on a Thursday morning and traffic was more manageable and he made it fine. Our hosts arranged for parking right outside the apartment, which was great. So if you are coming by car, look very carefully at directions ahead of time and be aware that large vehicles may struggle (it is doable, but challenging and you need to allow extra time). For departure, our hosts arranged airport transfer for my in-laws and it worked very well!