We stayed here with our two kids and it was a perfect fit for us. The kids were able to each have their own room, both of which were pretty spacious and could also probably be used by other couples. Overall, there was a lot of room in the apartment, and it was very clean and well equipped for our stay.
While not in "central" London, this is a great location, with a tube stop very close by and several pubs, cafes and shops to get what you need. You also get access to an amazing, large private garden/park area (shared with the rest of the crescent block, but only for access by residents).
Eric was very responsive to all of our questions and any needs that came up before and during our stay. The check in/out process is also very easy as there are key codes for the building and the flat, so you don't have to worry about arranging to meet someone to get into the apartment when you first arrive. We never actually met Eric, but he turned out to be a great host for us.
We would definitely stay here again.