Our stay at Ha's place was great.
He provided any help (e.g. he offered us a phone charger or gave us the opportunity to use the kitchen and all the kitchen items). The friendly atmosphere and the information about nice spots in London, gave us a really good feeling.
It's definetly worth it to book this room.
Plus: the bus 199 starts in front of the building and reaches the tube station Canada water in 7 min.