jp server in short:
new stats system, no karma system yet, no high lvl maps (liao etc), updated hefie (but no clan wars etc), gold from mobs depend on mob lvl (higher lvl mob = more gold), no 2nd role, hz/nan = pvp map, skill exp (own/self buffs was like 1% per cast) rest (nukes, smashes) was similar or lower than us version - but in village You can buy manuals c10 and upgrade it, very stable connextion (no lags), nice events (but no perma events like 2x events, etc), no blue spam, low but nice population, quest line with item mall items (like in all other 9d except us) - def smash/nuke ftw in pve here, different wan daye colls, different rewards from dungeons (bosses drop 'gloves' - use it on normal map and get reward: elixir or pills), CC or CoC = no poison, dont need herbs, chests in BP drop pills, etc
jp sux ? - no, its different
vn highest exp, skill exp + blue spam massacre + hackers kingdom, connection problems (lags)
us (acclame) aka 9bugs, pay & pray version, all cry (about bugs, old stats system, no balance, adbar[yet], neverdending tech issue with GMT & scripts, etc), pay & play
kr - kssid req + verification, closed for outsiders
hk - test in progress