Brendo, thank you for chiming in here... I just learned something new; I didn't know that the drivers have larger coils. Are you referring to the woofers? I know that the Brystons use 8 inch woofers and the Axioms use 6.5 inch. I would assume, if correctly, that the larger woofers in the Bryston would have a larger coil, but I never knew the specification.
I do know the cabinets have more internal support and a 1.5 inch thick front panel alone with a different tapering profile. Yes they were built to James Tanner's specification and it certainly yields a super nice platform.
What I enjoy is that Bryston collaborated with Ian and his impressive manufacturing facility to build what I think are wonderful speakers. Plus the workmanship of the cabinet veneer is outstanding, they are gorgeous pieces. So much so, I ordered an EP500 recently and plan on adding in others shortly, perhaps in a matching veneer.
I agree, its great to see such nice partnership with these two outfits.