Call of Duty Modern Warfare 2 Hardline perk Review.
The hardline perk is a perk that reduce by 1 kill the number of kill necessary to reach a killstreak reward in CoD MW2. This perk is mostly usefull in hardcore. In normal mode it prevent you from using the stopping power perk. To compensate this effect you may want to use the scavenger or one man army perk with it. While the can be usefull to call an air strike I don't believe you need this perk as you become good at the game. It may be usefull to those who want to call nukes.