I can only repeat everything everyone else has said - the apartment is great.
We were met by Alexis, Sofi and Erol (his mother and father) – they helped us up the stairs with our luggage and they are all absolutely delightful. Although we took longer than expected to get through immigration and our bus broke down, they were still smiling when we got there. :-)
All beds are very comfortable – even the sofa bed - and the air conditioning was a big plus, even in September.
Washing machine, dish washer, all quite new and working, and the bathroom is perfect.
It is very peaceful and close to public transport. If you take the airport bus, you really don’t need a taxi – it definitely IS near enough to walk.
Upon our request to leave our bags in the flat a bit longer on checkout day, we immediately got an OK back from Alexis, although he had people arriving the same day.
Many thanks Alexis - I can only recommend this flat to anyone spending a few days in Istanbul.