One of the better Marriott's in the United States. Extremely expensive (even for Herndon, VA), very high-quality service. Decent restaurant, excellent location close to IAD. The TGI Fridays is right around the corner, also a movie theatre.
This is one of the great Marriott's that is still highly-prized amongst frequent business travelers. In 2013, Marriott is generally in decline compared to Hilton (that situation was reversed a few years ago), but this hotel is excellent.