Loadouts are not fine because of the masses spawning with DMR's which just smash vehicles into the ground, banshees warthogs ghosts you name it, people spawning in LOS of two people with a DMR = death isn't fine. Spawning with two stickies and just sticky-ing the living crap out of a warthog as it goes past isn't fine either.
Promethean vision isn't a problem because of people camping with it, it just takes any kind of aggressive play/skill out the game. I can't ambush someone or sprint-melee-headshot combo someone purely because of Promethean vision and i certainly can't hide with it as my shields recharge. If you manage to sneak up on someone it's instantly negated by promethean vision because the guy has a backup plan and is rewarded for not being aware as he can just lb-360 instantly knows where everyone is.
sneaking up to someone =/= sprinting up behind unawares and assassinating.