I enjoy watching a lot of Kdramas and like the new expansion.  However for better immersion, I would have preferred original Korean with english subtitles.  That option should be easy to do.  

Listening to a Josean character speak with a southern english drawl for me is a off-putting experience particularly after all the time invested in creating the new and immersive eastern environment.   

It's in the settings, I gave it a try a few days ago before switching back.
You can choose English, Korean or Japanese NPC voice language.

Would rather also see Korean music instead of that bombastic stuff you now get once you launch the game. In global labs you hear different music when you launch it and global labs is actually the korean client.