Aer Lingus vs. Air Canada

I would 100% pick the Aer Lingus option, to avoid transiting through Canada. As long as COVID is around, the fewer countries you pass thru, the better.

Agree with Balso. While I don't know what time the Air Canada flight lands in Dublin, the Aer Lingus flight from SFO historically landed around noon or 1:00 (I have forgotten which). It's a nice arrival time because you can generally check into your hotel, or at least drop your bags, get something to eat and then get into your room.

Personally don't think it makes much difference. I would try to determine what plane they might be flying on those routes. That could make a small difference.

That’s a very good point about not adding another country, thanks. When I booked the flight on AL it showed a meal was served on the 10h25m flight. My experience on other airlines is that food of some sort is served throughout the flight. When I look at the flight now it says that meals are not offered for this flight. Does anyone have recent transatlantic experience on AL that could tell me what their experience has been?

I flew Air Lingus about 4 years ago and found them to be close to a low cost carrier in terms of
Seat, service, food. I would avoid them and fly AC. Please check but I would be surprised if you need to go through additional hoops just because you are transmitting Canada

I'm looking at both the Smart & Flex for that and they both say Complimentary Meal.

https://www.canada.ca/en/immigration-refugees-citizenship/services/visit-canada/transit.html

Here's what it says on our Government website today.
Remember you all must be fully vaccinated.

Looks like you'll be fine.
Vancouver Airport is one of the nicest in the world, so you will be comfy here waiting for your next flight.
(Those of us who fly in and out of YVR always says a quiet "Ahh" when we land here at home!)

As I noted elsewhere, note that AC has a "reputation"

https://www.transportation.gov/briefing-room/us-department-transportation-secures-record-45-million-agreement-air-canada-settle

Can you book a flight on AC that is fully refundable?
If so, then I think you'd be fine flying AC.

I flew Air Canada last August, transitioning through Toronto and had no issues (that was even prior to the borders being open for US). From the time that I bought my ticket to when I traveled, the schedule changed multiple times. I didn't have any issue reaching their customer service and they were really good at working with me to update the schedule to something that would work for me at no additional cost. That even included changing my destination city from Porto to Lisbon and moving dates out. This was for a basic economy ticket.

I've heard that at the start of the pandemic, they were not good at issuing refunds for canceled flights, however, I'm not sure if that is still an issue. I know at one point, they offered me a refund when the scheduled changed, but I kept my ticket and just move the dates out instead.

You might check both airlines to see what kind of additional flexibility they offer. I know that Air Canada was offering vouchers regardless of type of ticket, but not sure if that is still the case.

I’m using United miles, so any changes I make would go through them regardless of what airline I’m on. We have enough miles that I could also book the AC flight if I want to. I could then cancel one of them when I decide what to do. I’ll have to think about that.