Fantastic hosts, check in & check out was a doddle and communication was quick. The location of the flat was great! The area, Gelata, has many many shops, restaurants, cafe's etc. that cater to both locals and tourists. There are tram stops under 10 minutes walk away that take you straight to central attractions such as the Hagia Sophia, Grand Bazaar, etc. in ~ 10 minutes - my advice would be to get a Instanbulkart which makes getting around on public transport so easy and reliable.
The flat itself was large and clean, with a lovely living room area for relaxing when you are in the flat. The views are probably some of the best you can get, being able to see the Hagia Sophia & blue mosque skyline. Not sure if there was a lift, we took a few flights of steps up to the front door.