The targetting shown is used for pin-point accuracy or whatever. You can just do normal targetting and blast away very quickly, switching targets and all of that, but then there's a more refined system (like in Everything or Nothing I believe) where you can move the reticule around and go for headshots, take out the guy's kneecaps, shoot the guy's arm to make him drop his gun, etc. It's actually really cool, and much better than what I saw in GTA