User blog comment:Argorrath/CoDWiki News - May 26th '13/@comment-10363123-20130526232944

From a realistic perspective, neither of those killstreaks would be very practical. Tony Hawk's Skateboards would probably allow for faster mobility, but would be near useless in most environments that aren't asphalt (sand, grass, etc.) and would not be worth however many kills it is. On top of that, aiming would be near impossible. Guitar Hero's Guitars would most likely replace a melee weapon, which defaults to a knife, so this would be an automatic downgrade. About the only bonus would be the ability to play music and draw enemies near you while teammates pick them off.

Although, if you combined both of these killstreaks, you would have the best assist class ever. While on the skateboard, mobility would be maximized. Being able to melee on the skateboard with a guitar would be better than a knife because a knife would stick in the enemy and be very hard to re-obtain. So a basic hit-and-whack with the combo would leave the enemy on the ground, you gone, and teammates to clean up the kill. So my vote goes to both.