I didn’t listen carefully and couldn’t have heard much even if I had... but my impression was that yes, it has a killer bottom. From what I can see, the 410 BA has the same 800 hz crossover that the others have which implies to me that the woofers get to be real woofers and let the mids and highs all go to the array, allowing the cab to go deeper and fuller in the bottom end.
@campbems says his stack of 2 210 BA’s doesn’t go quite as deep as a stack of 12’s but punches a bit more. I’d expect the same is true for the 410BA. Maybe @Jeff Genzler will be able to comment once he gets done with NAMM and has a chance to breathe.
I agree with you about 410, 610, & 810 cabs but this (along with perhaps the Barefaced models which address the problems inherent in those speaker arrangements in a different way) seem to be game changers. Dropping the crossover and shunting the mids to the array fixes the beaminess and the cutting the weight... it all works as far as I could see/hear.