You can get tweeter ribbons, midrange ribbons and full-range ribbons from several speaker manufacturers.
You can get planar magnetic woofer panels from several speaker manufacturers.
You can get electrostatic speakers, both pure and hybrid, from several speaker manufacturers.
What is unique about the Apogees -- and what you cannot get from current speaker manufacturers -- is a ribbon woofer panel. I think the ribbon woofer panel, with its (to me) amazing and unique sonic characteristics, is really the competitive advantage, and unique selling point, of the Apogees.
Dear Ron,
What's unique about the Apogees is Ked, he's the one who single handedly raised them from the dead here otherwise Apogees are mostly long forgotten. Yes, they had some great attributes but getting them there was always difficult. Aside from some nostalgia and curiosity not sure how many of us who owned them in the past really want them back again. Personally I'm over all panels, IMO their limitations outweigh their benefits, specially the electrically charged types that can't handle volume and start buzzing like an electric fly killer when you crank it up a bit.
david