What can I say? I have just been back to the United States of America for the first time in three years and, despite all the horror stories, I found all of the staff (I asume they were employed by TSA) at IAD were very courteous and even had a big sense of humour.
Inbound formalities were at a minimum as far as time-wasting was concerned. It took less than 45 minutes to get from the aircraft to the hire-car.