Some of the people checking your visa and passport
can be extreemly nasty
I've always remembered the time I went to Canada ( before you needed a passport) via GreyHound. I took the bus, because I was fairly young ( presenting a paper at a Science conference) and thought it'd be fun and very informative.
When we crossed the border into Canada, the riders were told to vacate the bus. We all left the bus.
After we were all off, a security person appeared in front of the group and snarled, while holding my suitcase, "To whom does this case belong"?
I went forward and said the case was mine. The security person snarled," Open it up". Then he said "Take everything out and placed everything on the road". This I did, with everyone looking at me.
He went through everything, and then told me to pack everything up and then told all riders to re-board the bus. Off we went to Montreal.
Nothing happened on the trip back to the US, via bus.
However, the next time, one year later, I returned to Canada via plane. Nothing happened when we arrived in Canada ( no passport required), no insults,no degrading of US citizens, no inspections of suitcases or briefcases..
I've never returned to Canada, but I'll always remember how I was treated, when I attempted to enter the Country , having traveled by bus.
It seems to me, that US citizens who travel to Canada via bus are discriminated against, versus those US folks to travel to Canada via plane.