As you can see pretty much throughout the videos, the weapons move as if they have a lot of weight. However, in the demo the controls didn't feel too heavy, yet not as "twitchy" as in COD (which, imho, is not a twitch-shooter at heart, though).
As far as I can see it in videos of brink, there is much freedom of chosing ADS or hipfire, which is great, as I like hipfire like in kz2 . Its so annoying playing kz3 beta and being forced to ads everyone all the time, with left-right strafing( sideways strafing). Interesting would be to hear how the guns "feel" , is it any recoil, or weight, or is it plastic guns , like in COD