We enjoyed our long stay at Ruben's & Steve's place in Kensington Olympia area. it was a small loft but ok for our needs during our stay in London as we were only in the room during the night.
Someone might consider it rather on the expensive side but given the prices in London, it is more into the value for money area than the expensive one..
It is close to the Kensington Olympia station although this station is only served via District lines on few occasions throughout the week; however overground runs from there which is handy sometimes and 2-3 other tube stations are within 15 min walk (or 3-4 bus stops ride away). very safe area.
Owners are very helpful and friendly; always a joy when your hosts are such persons.
Only small issue was with the cleanliness of the room as the cleaning crew did not come once to our room (there was probably a miscommunication somewhere) but in the end everything turned out ok, so no big of a deal.
All in all, i highly recommend the place if you need a place to stay while in London