I stayed in the Doubletree Dulles for 2 nights in August 2011. The bed was amazing. One of the best beds in which I have slept. The staff was exceedingly nice and showed that they really wanted to serve. The cookie at check in was also pretty awesome. While the hotel has Dulles Airport in it's name, it is 5 miles from the airport and had constant shuttles between. This means no low flying planes rattling the rooms.
I stayed on the executive level, which during the week has a breakfast area open on the floor vice going to the lobby. The omelet was great and there was a nice selection of french toast, cereal, bacon, etc. I ordered room service and really enjoyed the chicken fingers in a spicy sweet sauce.
The room was tight, but functional. The desk included AV hookups for the TV and a USB charging port. The bathroom had a stand up shower instead of a bath tub. Overall, this was a pleasant surprise and I will be staying here again.