I can tell you are lucky if you can stay at Denise's place.
The place was well-organised and neat. Denise and Trevor explained simple rules to keep the house quite and clean which were also good for myself.
They were very helpful. They always answered my enquries quickly. They had prepared various versions of the direction of home. Once I informed them of where I was coming from, they explained how to get their place in details.
They were also thoughtful and friendly. Got my flight delayed, and they were waiting for me until I arrived late in the night. They got me a card and a little souvenir which made me feel welcome. We talked and laughed a lot during the breakfast.
Since they were living in London for a long time, they knew London very well. They gave me useful information about what to see, where to go and how to travel.
If there is any chance, do not hesitate to stay with them.