Modern Warfare 2's Dual-Weilding "Akimbo" Perk Explained

FourZeroTwo of Infinity Ward writes:

"Now to calm some initial fears of "OMG! Overpowered!". Akimbo is limited and balanced, just like EVERYTHING in the game. It's limited to sidearms, harder to aim than standard and you can't go ADS (aim down sights) since you have a weapon in each hand; Among other balancing techniques, so don't freak out before you see it in action."