I my self only learned of Axiom in late 2013. So only know V.4
most likely there has to be noticeable difference in all Versions or why else would they keep updating.
As I've come across in these forums there's already a big difference in the tweets as they've changed them from a plastic cover. So there's likely material upgrades in other components {Woofer, crossover,cabinet}.


Sounds like audio bliss mojo though the room for the equipment would make the bliss of the components shine.