Dear @mglik : I owned and own vintage Grado cartridges and till today no one of them ( including " the tribute ". ) disappointment under playing by its quality level performance.
" Optimized Transmission Line " was what Joseph Grado named to a totally new kind of design inside his first MC and latter on inside the Signature models as the XTZ and other models on this series.
That kind of new design dissapeared when those vintage Signature Z series gone out of the market but the white papers about were inside Grado company. Any one that lisened the XTZ knows that today could be one of the best cartridge quality performer out there. Maybe your Epoch 3 shares that cartridge motor design that’s a unique one and only Grado has it.
Btw, about that special ellipthical stylus in the Epoch 3 could be one of two other than ellipthical stylus shape used by Grado but unfortunatelly came only with a name but no description of the tip shape. One was named just: Grado tip and comes in one of the Grado samples I still own and the other is the one in the Signature family of the XTZ named: Twin Tip and maybe this is that " special ellipthical " in the Epoch 3 and I think this because today there is nothing really NEW on top stylus tip shapes: everything we can imagine stays already in the market.
Anyway, again thinking loud.
R.