What a wonderful pied-a-terre in London! The mews house is perfect for a family visit. We enjoyed a very happy winter week there--the blissful quiet of the mews, the very central location (easy for both Paddington and Marble Arch tube, plus the Edgware Road buses), comfortable furnishings. Definitely one of the best--of dozens--of AirBnB and home exchange experiences.
The beds were extremely comfortable (an English king in the big bedroom--slightly larger than a US queen; a double/full in the second bedroom; a full futon in the kitchen). The heating, hot water, washer/dryer, kitchen appliances, wifi worked perfectly.
Other than "reserve immediately," my only advice is (a) bring facecloths, (b) it's a high-end Nespresso machine, which takes the Vertuo capsules, and (c) if a light sleeper will be on the futon downstairs, load a white-noise app onto your phone/computer to mask the hum when the boiler goes on (yes, the downstairs is so quiet that this constitutes a noise).