I'm torn about writing a great review because the increased popularity may cause the place to not be available the next time we visit Istanbul! Mahmud was a great host with great advice and always available to help and the apartment was great for our family of 6. Everything was as indicated and illustrated in the listings.
It's proximity to the major sites and to eateries allowed us to do a lot of things that we might not have done because the weather was pretty bad with rain/sleet/snow for several of the days we were there.
We hope to book the apartment again during our next trip to Istanbul and there will be one!