The flat is great and very close by the tube station (no more than 3 minutes walking), also close by the airport (20 minutes door to door taking the tube) and even to go in the center of the city (20 minutes by walking or no more than 10 minutes if you take the tube).
The only thing is when we went there, there was a scaffolding on the whole building where our apartment was located, with noises of work from 9am in the morning ...
A part this point, very happy about our stay, and the kindness of Isabel, waiting for us when we arrived.