We had a wonderfull expirience at Dave's place. The place is very clean and homie, there is everithing you need. Dave provided us a map of london, gave some recomendations about where to go. Additionally he provided basic food for breakfast, milk,tea and coffee.
The area is very nice and clean, rail distance from the city (about20-30 min) or an hour by bus, that are much cheaper.
Dave explained us about the public transportation in london and provided oyster cards. Our recommendation is to bye your own oyster card, it costs 5 pound and you get it back if you return it. So that you can use public transport from airport to the apartment and back. Anyway very recomended apartment.