We were four people staying at Lisa's place and we were very happy with our stay. It's located near King's Cross station from which you can get just about anywhere in the city, and as far as I know it's one of few larger Airbnb apartments (3 beds counting sofa bed) available centrally in London at a reasonable price.
As many have mentioned there is some sound from the subway as it passes but unless you are extra sensitive to such things it sort of slips into the background after a while.
Definitely recommend.