I have a Nexus USA card and have been sent for inspection numerous times of why where I went to Canada and my car checked. It has made me not too happy and eager to go up to Canada now. The problem are the USA agents upon return seem to be not fond of its Citizens wanting to leave America and visit another place. To be fair 75% of the time they dont hassle upon return. But its still a pita to feel like a criminal upon returing to your country. Canada agents are always cool coming up.
Its the opposite situation on the Mexico border. Both sides welcome commerce and the $$$$ going back and forth.
The US guys can be real pricks, I even saw this guy on the Border Security TV show he is very zealous. I have been run in numerous times and even after the dog search and two hr wait they still treat you like a criminal. The guy asks, "anything you want to tell us?" Yeah Im going to be late thanks to you guys, after a staring contest the prick gives me my documents and Im good to go. Seems like they want to give you some rope so you can hang yourself for them, I hate that BS.
Overall I still go down its great if you get a shipping address down there and all your Amazon crap ships free, you just go get it and bring it back. I tell the Canadian guys I have $400 and they dont even care, not collecting duty is their way of being on strike and thats whats been happening. Just never ever admit to the US guys you have even smoked pot, that can get you a lifetime ban, how ridiculous and frivolous when the Pot shop is right across the border, thats fucked!