First, off..EMP's are broken imo. It's the only grenade that works through walls. To give you the worst example, on hijacked you can be hit with EMP grenades while under the deck when someone throws them from up top. They also end up working through walls. For their actual effect, 10 seconds and just 1 usually destroys guardians and sentry guns. If you carry 2 then BOOM kill streak is destroyed, including A.G.R. which survives rocket blows. They even kill dragonfires.
Concussions also are incredibly strong. Lasting 10 seconds completely immobilizing people. Flash don't last that long and you need to hit them in front and even then you can possible still see well enough to still fight. Concussion lands anywhere around you and you're paralyzed. Plus you know what type of affect you have when concussion hits, I don't know what I'm getting with flash grandes.
Just run around with tactical wild card and load up x2 flash and EMP, and just launch them all over the map. with scavenger it's one of the most annoying things in the game...I love it.
Kill one man, You're a murderer. Kill 1,000 men, You're a king. Kill them all....and You're a god!
Seeing as how you cant just sneak up behind a sentry gun and knife it to disable it....the EMP is the next best way to disable enemy electronics.
Concussions are the same way they have been in every single other CoD before this. Theres nothing wrong with them and if you honestly are going to complain about them its because Treyarch removed all other "Broken" things and so you've ran out of things to complain about therefore you chose to complain about concussion grenades.
in BO1 the back up complaint was Ghost/Flak Jacket
Do you know what EMP means? A wall isn't going to stop it. It works how its supposed to. It fries electronics, rendering them useless. And missiles taking down planes? Hmm... Maybe because it explodes on impact and those planes are full of gas, which is highly combustible.