David is a wonderful host. The location in Knightsbridge is perfect for seeing much of London very easily. Harrod's is a short walk as are Hyde and St James parks and the Victoria and Albert Museum and Natural History Museum.
The flat was spacious, comfortable, and just as described. The hosts are easily reached if needed as well as helpful, informative and accommodating.
We were here for 9 days and couldn't have picked a better place.