I feel like every time I've transited in YYZ (US > Int'l) over the past few months, I've encountered a slightly different experience. Not sure if they'e still tweaking the process or what, but I have to say my last connection experience On Oct 28 was fantastic.

I was flying SFO-YYZ-AMS on AC756 and AC824 with a scheduled connection of just over an hour. But AC756 was running ~25 minutes late, so I was getting worried (esp. given limited overhead space on the A330 that was operating AC824). But I ended up getting from gate to gate in just under 3 minutes, with no need to re-clear security or go through customs (there may have been a quick machine interaction; I can't remember for sure). Fantastic.