Fabulous location within easy walking distance of the Capitol, Library of Congress, Supreme Court and -- most importantly -- the Capitol South metro station. Lots of terrific restaurants in the area. We stayed three nights and got in the habit of stopping at the Hawk 'n' Dove for a nightcap on our way back to the unit. They are open late and offer great staff/service/hospitality.
The house is beautiful, lots of character. The unit was clean and stocked with just about everything you could want. The AC worked great (wonderful considering the heat and humidity of DC in July!). The bedroom was quiet and we slept well.
There isn't a lot of space in the bathroom to put your stuff; a minor inconvenience. There also aren't a ton of outlets but it was fine. The kitchen is pretty well stocked, with even a few food items (butter in the fridge, snack-size bags of popcorn). We bought coffee, milk and soda and had brought fruit and snacks with us. Grabbed breakfast out. The Pret a Manger a couple doors down was very good, and there's also a Starbucks nearby. The locks are a little idiosyncratic. Be patient and fiddle with them a bit.