The core shooting? I've NEVER seen COD have a weapon that can lock on up to 6 people and take them all out at once. Or have a heavy explosive weapon shooting like a freakin assault rifle (That seems like Unreal Tournament to me). I can agree that its pure adrenaline but at least put it in a category with the other Sci-fi futuristic arena shooters.
Yeah the gunplay is certainly not CoD. Just because it's twitch doesn't make it the same. I doubt anyone would say CoD and UT/Quake have the same core shooting mechanics.