So, every time I've returned to the US from Canada, I've done so at YYZ. Worst I've ever faced there is how incredibly busy it can be at times.

On the 18th, I'll be returning through to the US through YUL, an airport I've never been to. And I've been reading up a bit and... it just sounds like a nightmare.

So, some questions:

YYZ goes check in (to get bag tag), then preclearance hall for CBP, then security, then off to the gate. What I've been seeing is that YUL swaps the middle two steps, clearing security before doing CBP. Is that correct?

I'm seeing a recurring theme in complaints that officers refused to let people even enter the security line if they weren't in real danger of missing their flights, and that the line itself was effectively being constantly re-sorted by flight departure time rather than arrival-at-line time. If I hadn't seen the same thing in multiple reviews/complaints I wouldn't have taken it seriously, but it does seem to come up again and again. Is there any truth to that?

Anyone with experience using Global Entry: again, a lot of complaints. People report that although they have the kiosks they essentially always spit out an 'X' and send you into normal processing, and that there's no expedited security for trusted travelers. True/false?

I'm at the point of trying to plan my last day in Montreal, and working out when I should arrive in order to clear everything and make my flight (US Airways to PHL, for what it's worth), so any information from people with experience of YUL would be useful