We drove to Vancouver from Seattle a couple of years ago. There were long lines--a summer weekend--but the officials were polite to us.
The next year we flew into YVR from Reno and again, had no problem. 2 times to Canada and no problems on entry.
Although, once we had been on a cruise in the Mediterranean where we visited both Egypt and Israel. On return to the U.S., we were standing in the long customs re-entry line and our line was moving very, very slowly, while the lines on either side were quicker. I hesitated to move by using my grocery store experience--if you see a quick moving line and move to it yourself, then the line you've moved to ceases to move and the line you moved from then begins to move quickly. While moving out of line to check out other lines, I noticed that the customs inspector in our line was wearing a yarmulke. I figured if he's questioning everyone this long, we would be questioned even longer having been in Egypt then Israel, so we moved to a different line (and got through quicker).