I had a connecting UAX flight at IAD yesterday. When I looked at the departure monitor, it said the gate was D4X. Slightly confused, I walked to the D4 gate and waited there. They were boarding another UAX flight from the D4 gate so I started to wonder if I was at the right place. An UAX employee assured me that I was at the right gate, so I figure it must be a magical gate hidden between two gates like the invisible train platform in the Harry Potter I movie. When it was time to board, the UAX employee opened the emergency eXit door next to the agent counter and directed passengers to walk down the fire-stairs to the plane. I was disappointed that I didn't have to run through the wall to the invisible gate.
So, after spending all that $$$ on building the fancy G concourse bus stop and terminal, the best UAX can do is have people board from the emergency exit? No magical hidden gate at D4? I must say, that's ghetto.