So those CEA-2010 measurements seem to indicate this punches as hard at 20 Hz as the Starke SW15. That is damn impressive both price-wise and for its size, I think, and even though its not quite its strong suit, it speaks well for the performance of the sub.
I would worry a bit about port chuffing with that amount of output from such a small box and narrow port, but I suppose you didn't hear it in your testing?
Thanks for a great review.