Amongst all the server problems I've noticed something...

Some games I cant kill anything, its like I'm half a second reaction time behind my enemies when face to face.

Sometimes I can empty a full magazine into my enemies before they die, but they only fire once or twice to kill me with similar weapons?

When I watch their killcam, its like I didnt even see them and they are half way through shooting me before I seem to react (so I know they arent getting headshots) ?

However, on some games its rolls reversed and I can kill just about everything. One game I played was joyful as if I was invisible. Noone hardly reacted to me, so I just ran round killing everything

Anyone else experience this? and if so why is this happening?