The Churchill is walking distance to the vast majority of Central London highlights. Under 30 minutes walking to:

Mayfair & Hyde Park
Knightsbridge & Harrods/Harvey Nics
Buckingham Palace on the Mall & Green/St. James's Park
Leicester/Trafalgar Squares & Soho/Covent Garden w/ the West End theatres on Shaftsbury
Notting Hill & Portobello Road

The downside of the Churchill is that I didn't say 15 minutes walking.