Stay here if your focus is to visit treassures of knowledge on museums AND if you are fit to walk for a number of hours.
Expect simplicity and practicity, no luxury. Be sure not to bring a car :-) you wont need it. Subway, british library and british museum are walkable. Buckinham (say hello to Camilla for me), London eye, big ben and others are walkable.
1hour metro to LHR
Stay on an executive suite, ask for 4th floor for zero noise... after walking so much, you are going to need it (no elevators, luggage will be a problem if you are not fit).
Made breakfast on mini kitchen ourselves.
Pubs and restaurants near by
Brgds Daniel