Since Lighting 2.0 was added to the game, I have noticed that shadows don't work correctly in certain places if you are using DX9 (or DX9EX) on Medium or High shadow settings.
This is most notable on DS9 in the Tailor's alcove and in Admiral D'vak's former Task Force Omega office where the shadows flicker heavily as you get near these rooms. In the Tailor's room it even looks like the lighting system is treating part of the wall as a window it can cast light through.
In a similar manner, the MACO Shield reflections cause problems with shading and it creates a "flowing" shadow shimmer.
If shadows are set to low or even disabled, the shadow flicker goes away. Likewise, if restart the client in DX11 with Lighting 2.0 enabled, the flickering shadows are gone (or at the very least no longer noticeable).
Video evidence:
https://www.youtube.com/watch?v=LywMVdBwpBA
Also, despite having reduced file streaming checked, are map-change loading screens supposed to occasionally get "stuck" for several seconds after hitting 100%?
My video card is a Sapphire R9 270X with 4GB of VRAM.