The place is very clean, it is located in a quite good position, close to several bus stops and a train station, there is a M&S supermarket nearby, though I did not manage to locate a good cafe or restaurant, but you can find some at North Greenwich underground station which is really close. Communication with the host was fine, though not necessarily very effective.
Yet the apartment itself is definitely not suitable for longer periods of stay - it is rather small, and can accommodate 3 persons only if they have very little stuff (which is not likely if you arrive for more than, say, 3 days). It is also very dark and quite humid, also it was really cold, though I was staying in June. The flat is on the ground floor, one window facing the street and waste containers, the other opens up to a dark inside yard with old trees, so there is almost no sun inside.
The most annoying problem is the water - it was either burning hot or ice cold, and it was impossible to take a normal shower.
So choose this place if you're not too sensitive for details and environment.