We booked it for a month but ended up staying for 2 weeks because we found a permanent place to stay in London.
It was a nice, small flat with enough equipment. There were a lot of leftovers in the kitchen and fridge which could be removed before hands. Also it takes a while and you need to close all doors so the main room becomes warm.
Overall, it is worth it to give this place a look if you want to stay close to the center of London.