totem: Not quite - both the ATN13EaV and the ATN13EaX are downgraded versions (with bonded, comparatively blunt ellipticals, but still on a tapered, anodised alu cantilever), whereas the sharp elliptical nudie is the "plain" ATN13 (plain in the sense of without further suffix).
Jeff: As I've never seen a retail-packed AT13EaX, my guess would be that this variant was OEM only (over here as stock cart on the Saba PSP350), but otherwise the same as an AT13EaV - apart from the EaX initally sporting a (somewhat darkish) green needle (whie later ATN13EaXes were just as orange-red as the ATN13EaVs). Initially there was a slight difference in the radii specs on the Saba-packed original replacement needles, though: 9 x 17 µm for the (green) Eax, 10 x 18 µm for the (orange) EaV (on the Saba pack explicitely marked as replacement needle for the AT13EaX) - grinding specs typically aren't exact to 1 µm, however, but more like x +/- 1 µm, so it would seem pretty likely that in fact both simply were 0.4 x 0.7 mil.
Greetings from Munich!
Manfred / lini