The dirty trick all top MW3 players use
If you are looking to gain a serious advantage over other MW3 players this MW3 Quick Scope modded controller is exactly what you have been looking for. This is the best modded controller I have ever used, it is packed with many useful features. It includes an adjustable timing option for quick scoping which is just sick, dual rapid fire, auto aim down sights when pulling the right trigger, and the sync button toggles modes.
It works for all semi-automatic weapons as well, which basically turns a semi-auto weapon into a full auto weapon (this is a ridiculously awesome feature!). It also has a really cool looking Modern Warfare 3 skin with MW3 stamped on it! If you are looking to gain a serious edge in MW3 and on a tight budget, this controller is exactly what you have been looking for. The price/performance gain you will see from this MW3 modded controller is insane!
Sniper Quick Scope
Drop Shot Mod
Auto ADS (aim down sights)
Zombies Auto Aim (for Zombies in Black Ops)