Tried it out and two things really kills the fun for me:
1) I can't tell my squad to get the fapp down and stay out of sight.
Makes approaching a group of enemies undetected near impossible.
2)AI seeing you through foliage and hedges...
I'm prone in some grass, can't see a thing because of it, go over the top of a hill (still "hidden" in the grass) and BAM headshot from some sniper I couldn't see.
Same thing with hedges, shrubs etc. Seems like anything that can be shot through is transparent to AI.
I could name a few other things that I find quite annoying, but those two are the most important points...