We stayed for a week with our 15 year old twins. It was a perfect spot for a home base. The location can't be beat. The mews is quiet and private but just outside the automatic gates is everything you will need! The Tube, Boots, Pret Manger, M&S Food Hall, etc were right there. With that proximity comes the slightest bit of noise. You can hear the rumble of the train inside the flat but it wasn't bothersome. There is also a school right behind the flat so the kids can be a bit noisy in the morning.
The flat was modern and spacious. Master bedroom was really big with plenty of storage. The third bedroom is pretty tiny so you should be prepared for that when assigning rooms. The third floor is a great little office space with another full bath and the balcony. Kitchen is well equipped and the host is great at communicating.