I can only say positive things about this experience.
I would raccomend this apartment to anybody. We are a family with a child of 7 and we felt like home.
Marion is just the perfect host. She was nice and helpful even before our arrival (we had a late flight and she helped us with Oyster card to get to her flat so late at night).
The apartment is very clean and spacious, just as described.
It was nice to have long talks with her, before going to bed.
The neighbourhood is nice and safe, the tube station is just 5 minutes walk or you can get the bus right in front of her building.
We would definately come back to her, next time we go to London.