As a DC based pilot, whose first or last leg is normally between DCA and IAH, I can only recall maybe 3 or 4 times we had the jump seat occupied since the merger. A small sampling I know but generally I haven't seen jumpseaters between those two airports. How Dulles is I have no idea, but chances are there are more pilots trying that city pair then going to DCA and with fewer flights (though some tend to be 767's)
A few points to ponder as well:
*The Airbus has 2 jumpseats.
*A UAL pilot can not be denied the jumpseat due to a weight restriction on a UAL mainline flight. Many agents/operations are not aware of this so it would be handy to have a screenshot of the FOM page. I had to use it (including showing the FOM reference) last year going DCA-DEN.
* Metro (the subway in DC) is going thru a year long safe track modernization process. Expect a lot of delays dependent on which line they are working on that week.
DC