Terrible experience at Dulles on two separate occasions...1.5hr queue for passport control on arrival and then 1.5 hr queue for security on departure. Not a developed world experience by far...
Not impressed with the airport. Very few shops stay open 24hours so if you have an overnight flight, you're screwed. There are charging stations which is a plus, but definitively not enough.
Tip: If you're riding in coach class, then please don't use your Louis Vuitton luggage... It makes you look funny. Save your money and use your Coach brand luggage.
If you are going to D gates, don't take the train to the "C and D gates" it drops you off in the middle of the C gates. The other tain drops you off in the middle of the D gates.
Hit and miss on the terminals. The international terminal is very nice. However most are small dingy and crowded. Pay close attention to the Train and bus routes.
Southwest terminal is tricky. It's in "section" 1 of the four in the only departure terminals. Then it's literally on the back of the area facing the tarmacs, behind the other check in desks.