Recent experience, the Royal part of the check in process was flawless. The problem is that Vancouver merged three ships boarding experience at the same time.
We had an 11:00 - 11:30 check in time. We were there on time despite a ton of traffic, right at 11. You board an elevator to go upstairs, line for that. You get upstairs and go to the Royal check in, which took < 10 minutes. You come out of that and are herded to US customs. You're merged with the passengers from the three other ships. You enter a Disney World line of snaking lines to get to a security check. Pass through that and you get to another series of snaking lines to get to US customs.
We were on board by 12pm, so only an hour. We heard horror stories from people who arrived at 2pm and were worried they wouldn't make it on board by 5pm (got on at about 4:30). Highly recommend arriving early. If flying in the day of the cruise, consider flying in the day before.
Second Arrive Canada thing never got used. You only pass through US customs on the way in. On departure day, Canadian customs collected our pre-filled out form and did nothing else. Basically walk right past.
Thanks for folks who helped me. Hope this helps others.
Jeff