Archangel armor, available late game, gives a soldier the ability to fly. What are the considerations when deciding whether a soldier should be covering or hovering? Does one provider better offense or defense than the other? Does altitude affect anything other than line of sight?
Hovering gives a better vantage point (better LoS), can trigger the "Height" bonus if you're high enough, and additionally acts as low cover (-20% chance to be hit, just for flying).
If high cover is available, that might be preferable, or if you need to hunker down (not available while flying).
One other thing to note is that Sniper's don't benefit from Low Profile when flying, so you might find them getting hit more often than you're used to, should they start taking flak.
If no cover is available, you should always be flying.
In fact, archangel armor is not good as imagine.
Damn Good Ground only effect when you STAND, not effect when you hover/fly. For sniper, climb rooftop/hill, take cover is more useful than fly.
Low cover got 20 defense, 180 degrees. Hover/fly got 20 defense too, but 360 degrees. If surrounded by the enemy, hover/fly maybe a choice to prevent flank shoot, but retreat is better choice.
A perfect way to use archangel armor is in terror mission, map small, chryssalid and many susceptible people, just fly and shoot.
Not tested of angle's LOS, but sniper use
squadsight, it's not a problem.