Been playing this for about 10 hours now, on act 4 of the Wei Campaign. No graphical bugs, game runs a solid 60 FPS at all times, even on busier areas. Had one character that had some glitchy robes, but disabling SPU looping fixed it.
That said, there is one major bug. Whenever you enter an area that is on fire, (i.e. Luo Yang), the screen overlays the first frame of gameplay over the screen and stays frozen until either the fire goes out, or the screen zooms in on an officer. The minimap works, and healthbars are visible through the frozen screen, so you can still progress. Oddly enough, if you are in an area that gets set on fire a few seconds after you enter, the game is fine. The glitch only occurs when the fire is there to begin with.