Here is a review of my experience this week.
VA1 arrived a bit early, even though in the rear cabin, we made quick progress to Immigration. Got directed to a line with about 10 people in front, went really quick, even after having a chat with the officer

As we made our way to the baggage carousel, the line out at customs looked ok. Got 3 out of 4 bags, then 1 was held up because the belt had a problem, after 5 - 10 minutes, it started again and bag popped out. By this time, the line was extending out the door from the customs area, as we approached, they opened up the other side and we went straight through and headed towards the Air Canada checkin. All up I reckon it took 30-45 min.
Air Canada checkin, however, was a disaster! The line to print our passes and bag drop extended past the cattle run, then across the walkaway and along part of the wall. It was a debacle. Cramp area, not enough staff, those there took their time and got distracted by anything and everything, people waiting to get labels attached to the bags. When done, the original line had grown by about another 40m.
Went through TSA security and had about 40 minutes spare before departure.
All up, TBIT was a dream, AC a nightmare. (Boy, hasn't TBIT changed from that dark and dingy place I remember from 3 years ago)