Seems like US customs are lenient, but I guess having a machine that was manufactured in your country changes everything. From my experience, everyone who's bringing anything back from the US whether it be a magazine to a t-shirt has a target on their head. They're money hungry and I'm sure each officer has a quota to meet which is why you'll sometimes get a pleasant officer or you'll get that power-tripped guy/gal. I don't know why, but every time I enter the US the customs officers are super chill. Sure they ask the typical questions but it'll end with some sort of humor for example, one officer asked if I had a dead body in my trunk, or another asked if I am hiding any terrorists . Canadian customs need to lighten up a bit. But in the end I do respect them for keeping our borders safe. That's what it's really all about right? Or just increasing the bottom line for our government LOL.