1)I'seen some topics saying that soldier do not stop after spotting an alien. Not true. However, animation is quite deceiving because there is no delay on it.
Assuming a soldier is ordered to move from X=1 Y=1 Z=1 to X=4 Y=12 Z=1 (just made it up).
That soldier spots an alien at X=2 Y=6 Z=1 and halt.
It really happens this way so far.
But as soon as he starts the movement, the alien gets visible since the first step, and the "vision line" is not drawn from the alien to X=2 Y=6 Z=1. It's intead drawn to the movement starting position at X=1 Y=1 Z=1.
This leads the player to think alien was spotted on the beggining of the movement, when it was not.
2) Assuming an previously unseen alien gets out of cover on aliens turn and kill a soldier (I'll assume alien is using a kernblade to be more ilustrative).
The soldier death animation happens as soon as he gets visible to the player on his movent towards the soldier, not when he actually reaches melee range. This leads the player to believe the alien "meleed" the soldier from far away. Not true, its working as intended. But the animation timing is kinda wrong.
3) On Alien's turn, even when whole alien movement happens within soldier's line of sight, currently we see fragments of it. Player should of course, see ALL alien movement (and actions) happening within his soldiers' line of sight. Maybe even at a lower animation speed as X-COM (may require some coding).
Hope this report helps devs in any way.