I haven't been, so I can't say. From what I've read the tricky things are just the same as the USA - arbitrary stoppages for weird lengths of time (causing missed flights) by surprisingly rude or invasive people. Again it's just what I've read, but it stuck in my mind as unexpected because it flies in the face of the Canadian stereotypes.
Can't say I've ever had a problem, but then I'm also a citizen, which may make things different.