Please read other reviews re: noise (or surprising lack thereof).
The apartment is professionally soundproofed per UK Building Regulation Standards and the windows have 6" gap secondary double glazing (the wider the gap, the better the insulation).
So unless you are hyper sensitive you will never hear the road, trains, people, or anything else for that matter.
The apartment is in one of the busiest areas in central London so it is not like visiting the countryside. But that is the point. It is very central to everything you may ever want to do in London.
A quiet oasis amidst the storm.