The huge problem is that the AE flights at DCA go out of gate 35 which is the hole in the terminal that is always packed and a disorganized mess. You are lucky if there is one experienced AA rep in the whole place. The rest are all overworked miserable US employees. If you have a problem or need some info, it's really difficult.
For example last week, I was #2 on a 6 person wait list for DCA-JFK with 4 seats left. When I cleared, I asked if there were seats in First. The US agent said yes so I offered to dump an E500 so an extra person could get on the flight. They couldn't fathom this, they didn't know how to do it and a first seat went out empty leaving someone behind unnecessarily.