What if Perks and Weapons improved as the user skilled them up? They would have a cap on efficiency obviously, but it can only be achieved from consistent use. When someone stops using a perk or a particular weapon the efficiency will decrease over a period of time.
Eg: All Perks and Weapons have 5 levels of effectiveness. Cold Blooded at level 5 would make you completely invisible to radar and thermal sensors, while level 1 would make you completely visible -but having it equipped is giving you the chance to skill it up. Ninja would work the same way in regards to visibility on Heart Beat Sensors and the sound level of Foot Steps.
Weapons will still have varying levels of recoil. However, the more the player uses a certain weapon the less recoil will be. Eg: The AK at level 5 will still have more recoil than the Famas at level 5. And like the Perks, if the player stops using a weapon it will gradually downgrade.
What are your thoughts on this for the MW3 wishlist?