In my experience it is. I'm half Canadian. Pops and the majority of my rather large family are all from Mississauga. I've spent every single childhood Summer in Canada from ages 1-20 something, in total around 4 years of my life there. And there was a poster earlier in this thread, an American living in Toronto now who summed it up pretty similarly to what I felt. There is a underlying resentment, anti-americanism, and 2nd city mentality of one upmanship that many Canadians have towards America that doesn't exist in the reverse.
The shit became really apparent every time I would watch the Summer Olympics there with all my Canadian family.