PvP, and especially Iron Banner, goes better if you have a coordinated team (even half a team). I play with two others and we light it up. But then again, we don't go in with Sniper Rifles and Pulse Rifles. PvP favors Fusion Rifles, Shotguns, Auto Rifles and Rocket Launchers (in my opinion) unless you have a coordinated group that can beat down an enemy or two at the same time with a hand cannon or pulse rifle.
Sniper Rifles are ok in some levels if there is open area and you camp. Otherwise it's all close quarters (Firebase Delphi is an example of that).
Just my opinion