It varies for me, even at the same airport.

At EWR & PHL, my bag is always waiting for me on the carousel.

At YYZ T1, I've had to wait over an hour at times, while one time it was waiting for me on the carousel, even though it only took me 5 minutes to walk from the gate and get through immigration. My last few flights arriving at YYZ T1 have had to wait about 15 minutes for my bag to show up.