I love this hotel. Great location, and as has already been stated, the metro is close, restaurants are close, and the zoo is across the street.
I've stayed here for a convention and I brought my family here for a week to visit DC.
If you go, contact your congressman early so you can get on the list for a visit to the White House and a ticket to tour the Capitol Building while congress is in session. You will be put on a list to visit the White House, and you'll end up with a 1 in 3 chance of getting in. (You never know-but do this early) Also, your Congressman can give you many more ideas on where to go in Washington and what places require advance tickets, etc.
Have a great trip.