Yes, they're different speakers, not just a rebadge, but it's public knowledge that Monoprice licensed the same patented enclosure design. (And are calling it K-BAS instead of H-PAS.)
Speaker reviewers couldn't heap praise on this enclosure design fast enough, for the amount and quality of bass it delivers.
Monoprice is clearly using different drivers, so the question is, do the different drivers result in a speaker that's similar to the ATs, or inferior, and if they're inferior, by how much? (Or maybe the Monoprices are superior?! That's also a possibility.)
That's why we need a review! I'm afraid $500 is way above my budget for buying something just because I'm curious about how it sounds. Plus I'm not set up to do any objective speaker testing.