Been playing on ghost and being spotted and have reinforcements arrive then, is essentially a death sentence (actually depends on your positioning, but you have to run away anyhow).
Not that i'm complaining.
I think the game is very solid, but has some glaring omissions that are so weird, like not being able to drag bodies, or climb some objects.
Also, the big big big issue here is AI, both enemies' and teammates, and this can be alleviated a lot by playing with friends, in singleplayer it can be frustrating though.
The enemy AI is a lot more competent than team AI like Rebels IMO.
Its not been a huge issue for me, as they seem to mow us down in the open pretty quick.
Things like them running 1 and 1 around a corner as you kill their friends in front of them without a reaction to it, whoever, is a bit breaking.
I suppose that can be fixed but even then, I've enjoyed it