I'm coming back to this hotel!
I got this hotel room as a "Secret Hotel" deal on Expedia... and I must admit I was a little worried and anxious. But as soon as I reached, my frowns turned into a large smile. It is such a cozy and quaint little hotel, with such an EXCELLENT location. It is literally next to the Postal Museum (a Smithsonian museum), and a 30-second walk to the Union station. You can see the Metro sign from the front door of the hotel. 
Service is excellent - I arrived early, about about 1130hrs. Check in time is supposed to be 2pm, but the staff gave me a room anyway. I was given a corner room in between two storerooms (must be the special deal low price offer...) but oh boy! I was so thrilled! There's something about the cute pink wallpaper and the super high bed that got me all chirpy and happy as a bird in a bathbowl. It was comfortable, and the bedside lamp had a charging station below which I can charge my electronics next to me. The bathroom was adequate, and the usual amenities were there (sewing kit, shampoo, glycerin bar (!), shower gel etc). All made in Ireland. :-)
I had a great night's rest, and for breakfast, I popped over to Union Station to get myself milk and yummy danish. Union Station is a convenient station to be located next to. I went to the Holocaust Museum and the ride there took only about 20mins max. I could have taken lesser time if I knew how to use the ticket vending machine... 
Anyway, I will totally encourage anyone to give this hotel a try. Much more character than the usual international chains of hotel.