1e has a nice "into the unknown" feeling but all the stuff is scattered across a lot of different books. Also, the "ignore armor on named success level" thing can get a bit awkward since you have to consult a chart.

Subsequent editions tended to compile all of the game information into larger, singular volumes. But do not venture into Cathay, for its books are cursed by something worse than the Horrors. You can even read it in its name that it's as poorly thought out and ridiculous as the "theme park future" Theran provinces that are transparently just much more contemporary takes on the countries in question.

The present edition is 4th. It moves the time table forward and tries to center Iopos as the new threat in the setting post war against Thera.