This show is the American version of a show that originally started in Australia and which has since come to Canada and the UK. The Canadian version is dull and not very interesting, mainly because it shows routine incidents.
The American version is more interesting, probably because the Mexican border is way more exciting than the Canadian one and thus provides more TV-worthy footage. There are drug seizures. There is people smuggling. Because this show deals with the Department of Homeland Security as a whole rather than just Customs and Border Protection, the Transportation Security Administration and Coast Guard are also shown in a few segments; the variety makes this more watchable.
In addition, the CBP officers seem to have more personality than the ones on the Canadian show do. They have a laugh from time to time and are generally more polite even when they have to deport someone. In one episode, an officer nicknamed the "Rottweiler" is profiled. He got the nickname from tenaciously digging through databases to find information on travelers. These sorts of things aren't shown in the Canadian version.
One note though: in a season one episode, two Canadian citizens born in Iraq try to enter the US and are turned back. The voice-over mentions this detail once, but otherwise refers to them as "Iraqi nationals." I guess Canadians aren't scary enough for Americans.
