most patches are just 1:1 from KR by now (including every bug KR had at patch time, they don't include the fixes they had to make later for that patch), but they go the extra mile to remove the best rewards or increase the stage needed to grind for the western release for whatever reason.bugfixes (even emergency bugfixes) which are a week 1 patch in KR take sometimes up to 4 months to arrive in NA/EU.incredibly incompetent developers, be it performance or bugs (you can clear the highest possible stage with bugs, which is still not fixed).
from soulshield chests, KR can choose, EU/NA is RNG) In my opinion it's not worth playing anymore.