If you nerf PE then you'll waste the point of sneak, to observe,avoid and tell enemy location.
Squad of snipers don't even have to sneak to own you without you seeing them, there isn't a problem here.
Heavy snipers are ridiculous, sneak isn't a problem here.
Melee sneak - OP
Flamer sneak - OP
In general, I don't have problems with sneakers, I managed to find 90% of them. Sneaking involves skill, its not just pressing button and running in front of your enemy and clicking mouse. If anyone will mention snipers here, they can own you without sneak anyway.
About anti-sneak device - if something like that would be implemented, than I suggest player wearing it has to have high sneak skill as well. Because if you counter sneaks simply by having an item, and sneaker has to invest SP, buy stealthboy and is limited with an armor in a way than there should be sort of investment to make for anti-sneakers.
Or you could just make traps easier/cheaper and people can put bunch of traps which will give away the sneaker. Or some sort of anti-sneak gun, if you manage to shoot the sneaker his stealth boy charges are drained.
People don't even use hex shot, which is fun and good anti sneaker tactic, when you see door opening no one is there, burst a clip into the air, you never know.
Current AoP status in eyes of the players - nerf sneak,nerf snipers,nerf criticals, nerf aimed shots, nerf KD's, nerf BG,nerf EW,nerf Melee
And after we completely cripple the game I wonder what will be next excuse when losing a fight.