My family, including my 3 and 5 year olds, stayed at Matteo's flat for 5 nights. The location was amazing as its right in the heart of Knightsbridge, but situated on a very quiet street. There are lots of cafes, shops, and the Knightsbridge tube stop within a 5 minute walk. The flat was spacious and we really appreciated having 3 bedrooms to spread out in. We had warm weather during our stay in London and found that we managed just fine even without A/C since most of the windows open to let in a nice breeze.
Matteo was great to work with. Our 3 year old snuck one of the sets of keys into her "purse" and we didn't discover the location of the keys until we had boarded a cruise ship to Spain. He was very understanding about the mishap and the fact it took about a week for the keys to be returned.