I almost always went to crouch when firing at anyone in Ins2014 because crouching gave you more stability so you had less weapon sway. In Sandstorm, however, crouching takes off about half of the recoil you'd normally have while firing, effectively turning any firearm without any attachments into a laser rifle with little recoil control required.
Combine this with the new 50-round drum mags (which imo should be 4 supply similar to the Galil drum mags in ins2014) and buffed 5.56 damage and Security is disgustingly overpowered weapon-balance wise. Granted, I haven't played much PvP but I'm not sure if I've seen Insurgents win a single round of anything. Maybe once.