Flew out on Friday as planned.

Was indeed understaffed, and encountered a variety of rude folks (including rudest US CBP officer I've ever met, who took my GE receipt and used the opportunity to yell at me a bit for asking when called up if that really was the GE exit line, on account of it only having NEXUS logo). Non-AC US-bound flights were a mess, though, and neither the monitors in the terminal nor the staff seemed to actually know what flights were going to be where -- at one point monitors insisted my flight (US Airways to PHL) and an AC flight to LAX were both at the same gate, leading to some very confused passengers and AC staff.

Not the worst airport or border experience I've ever had, of course. But not exactly great either