My understanding is that the only difference between the two (besides minor styling differences) is that the Equator has a better/longer warranty.
So why do US News and Consumer Reports rank it so much lower than the Frontier???
"If you’re looking at the Equator, you also need to look at the Nissan Frontier. The Equator is a rebadged Frontier. Only cosmetic differences, a slight price difference and Suzuki’s longer warranty differentiate the two. They’re even built side-by-side in the same factory. Being a Frontier in different clothing doesn't hurt the Equator any, as the Frontier is a well-liked compact truck. In general, reviewers recommend the Equator over the Frontier, mainly because the two trucks cost about the same, but the Equator has a much longer warranty."
...yet in the end they rank the Frontier well ahead of the Equator. Doesn't make any sense.