This flat is an amazing find! Our family of four, including two teens, had such a wonderful vacation based out of our home away from home. It is a family-owned and lived-in residence. It has an artistic feel and is warm and cozy. There are books, games and puzzles for your use; a fully-equipped kitchen and tons of space. It's part of a complex with a private garden area, as well as being around the corner from Holland Park. The views from the artist's studio, as well as the rooftop area are beautiful. We loved being here!
Pros - close to public transportation (NHG and HSK tube stops are super-walkable, although take the tube to NHG if you have luggage or groceriers - it's a downhill walk); shopping at NHG or HSK areas; local churches (St. George's is absolutely charming); great kitchen and living areas; extremely safe neighborhood; convenient to every part of London; great Wi-Fi for all your trip-planning needs
Cons - beds and linens are not high-end luxurious, although quite sufficient for all but the choosiest of sleepers (if you're extremely tall, the beds may be a bit short for you; at 5'9" we were fine); no tumble dryer, but there's a closet for hanging clothes where things dry extremely quickly; lots of stairs, although we simply viewed them as exercise.
We just left to come home, but if we coud go back and stay again tomorrow, we would!