The building a new complex right (and I mean less than 50ft from the front door) from the Vauxhall Tube Station - this convenience cannot be overstated. We returned the rented car as we didnt need it - we went everywhere with public transport. The unit is also on the RB6 River Bus.
Lots of small touches - Many USB outlets (we didnt need to bring our own) and a nice large bathroom.
The beds were large and comfortable (UK King size=US Queen) and clean. The unit has a single unit washer/dryer and for bigger jobs, a Drycleaner is downstairs.
Also in the complex: Tesco Supermarket, a Petit a manger, and 3 restaurants. The 24hour concierge made it easy to check in.