It seems like the IAD flight schedule shows the A350-1000 but keeps getting changed to A359 for flights within a few months of departure. I have a flight booked for Nov that is currently 351 but I won't be shocked if it gets downsized later. I guess it sounds like the IAD route isn't doing great, but I think the non-daily schedule really hurts with any route. And the IAD-HKG departure time seems less than ideal as well.