The hotel is very well located, with all the amenities you need: fridge and TV, central air-conditioning that you can't really control, but it's good enough.
During your stay, don't forget that the hotel was built in 1914, so the bathrooms are very small, the corridors are a bit faded, and the rooms have limited space. (In the corridor, you have the impression of being in the movie Shinning).
When we visit Washinton, we're rarely in the room, always out visiting, so a clean bed, hot water and a safe place to stay is all we need, and the Harrington Hotel offers it at a very good price.
The Metro station is not far away, and the National Mall, J Edgard Hoover building, the White House and the Capitol are all within walking distance.