Flew YYC-YVR-YWG-YYC this past week...

ex YYC was a full A321. No enforcement at security. But at the gate - I counted 3 agents walking around the gate area asking passengers to size every carry on AND personal item. Anything that didn't fit was sent up to the podium, where a fourth agent was dedicated to checking bags in. Plus there were 2 agents helping pax as normal, so 6 total. Every personal item was tagged. I'd say half of all bags sized didn't fit. Biggest problems seemed to be ladies tote bags (those "carry all bags") and backpacks that are way too stuffed. I came and lined up with zone 1 (in J). An agent came by and asked each of us "are you zone 1" and when we said yes, she gave our bags a quick look, and walked by - no sizing, to tagging (granted all of us looked to be within the limits). Boarding finished early, and we left early. What I liked was:

1. It wasn't arbitrary - to police 190 pax, you need a few staff. Nothing worse than having one agent trying to size bags, because then it feels like you're being singled out (not to mention its annoying to see someone with the same bag that you had to check carry theirs on). Here, same rules for everyone (with a little wiggle room for zone 1). If you had to size your bag, so did almost everyone else.
2. They made you put it in the sizer - I HATE when agents eyeball a bag and say "too big, check it." Let me at least try to make it fit. Here, the agents had people test every bag. Surprisingly, I didn't see anyone fight or challenge this. If it didn't fit, they complied with checking.
3. They did it well before boarding - Realistically, you can't police carry ons during boarding. Here, everything was done before boarding, so I imagine it streamlined the process.
4. The agents were pleasant - The agents didn't act like police or call people out for breaking the rules. They were actually quite pleasant. They asked people to just confirm that their bags fit. If they did, they thanked them and let them go. If they didn't they told them it was oversized, but that the agent at the podium would take care of checking it for them. I imagine this went a long way in getting people to comply and avoiding any arguments with pax.

Meanwhile my last flight ex YYC 3 weeks ago (789) had zero enforcement anywhere.

In YVR, no sizing at security either. At the gate before boarding a full A320, no enforcement at all. The agent even helped on a wheelchair passenger and her partner, where each had an oversized roller, oversized duffel, and big shopping bags. Multiple people with suitcases + duffles + totes + purses. Sure enough, we were delayed because they *shockingly* ran out of overhead bin space.

In YWG, didn't see anything t security, and don't know if they enforced at the gate - I was on a CRA and it was maybe 80% full. I was running late and missed boarding, but found room in a bin within a couple rows of my Y seat, so I imagine they probably enforced a bit.

In typical AC fashion, consistently inconsistent. They've shown they can enforce the rules well when they want to, but forget about standardizing the rules. From what I've heard, the "cage" sizers they use are actually a bit bigger than the published size, but the electronic sizers are less forgiving, so I'm sure its only a matter of time until I'm on a trip where the bag fits in one, but not the other.