Going into Canada: there are a few visible cameras, the border agents sit at eye level facing the driver, the grilling is professional but courteous and they maintain eye contact during the conversation.

Reentering the US: the place bristles with cameras, the agents sit way above eye level and face 90 degrees away from the driver. They bark orders while facing their computer screen so you can barely hear them over the road noise. The overall demeanor is miles removed from the "Welcome to the USA" signs plastered all over the place.