I remember the first time I touched a EMX-1: it was 2007, omg? For that time it was just great machine (however, not as deep and rich on sounds like Roland’s huge boxes or Ensoniq stuff).
As for the sound, I think even with the better tubes, it sounds exactly like what it is: a 16-bit PCM aliasing engine, warmed-up or softened with analog tube circuit (and Korg’s famous compressed one-shot sounds just sum up to overall picture). It’s especially noticeable on a big system and it has for me some bits of nostalgia.
I liked more the sampler version, some of the effects were surprisingly powerful, like absolutely brutal ringmod on kick.