I enjoyed very much staying in M...'s apartment at St. Ronan's. The room, though not big, is very comfortable and, like everything else in the apartment - bathroom, kitchen - impeccably clean and adequately equipped. There is even in the kitchen a small fridge solely for the use of the tenants. And above all, the host is really friendly, warm and welcoming.
For light sleepers, however, the proximity of the room to the tube line, which at this point runs overground, might be something of a problem.
Otherwise - an ideal place for a single traveler in London.