heres what each lvl does:
lvl 1: you hear a chime sound when enemies enter stealth/ theres a green light around the enemy
lvl 2:increased visibility of cloacked enemies, still kinda hard to see cloacked ppl so you can hardy see them still so theres no difference :/
lvl 3:you hear a chime sound ( same as lvl 1) but you see green light surrounding the enemy and when you see that light move its a cloacked person so in other words you just shoot at the green light floating.
i just got it to lvl 3 today tomorrow i will be posting a video of it to show what i mean by the green light, this perk is one of the best when you get it lvled up like blind spot, stealth enhance.
if your thinking this perk is useless then consider this: do you want to run around undetected with blind spot w/ surpresser or do you want to see cloacked enemies and get the drop on em before they kill you?think of it like that.
my gt is gamer dude 1830( i wanted it to be gamer dude 18 but some one already took that gt name).