This is simply a list of issues I have experienced since DT. Reiterating, the game ran fine during the first couple of days, then it just started degrading.

-Stuttering
-Game freeze (varies from momentary to full freeze-up)
-NPC interaction delay (this has been mainly the npc that gives the hunt quests in Tuliyollal, but also various other npcs to lesser degrees)
-Extreme latency in 24 man raids (all of them)

What I have done on my end to attempt remedy:

-Lowered or turned off various graphic settings.
-Lowered Character Models displayed from maximum to normal.
-Restored/repaired game files via the launcher
-Full System maintenance. (includes dism and sfc commands)

Nothing I know to do on my end works, at least not permanently. It'll be better for a short time then it all starts again.
I have not had the directx issues... so far... or some of the other issues people seem to be having. From what I can see, the stuttering and freeze are the most common complaints, but I'm definitely not the only one experiencing the latency in 24 man raids.