I know the whole point of them is to give an advantage, but I really think they spoil the COD games. You could be enjoying your game, then someone just uses one of those that require no skill at all to kill you.
You could of even just respawn'ed then instantly get hit with one.
For the next game get something else in..like the little RCXD cars from Black Ops.
I think they should keep the different kill streak classes, i.e. Assult, Support and Perks. I know some kill streaks are going to be different but in general they're the same. I do like not having to get a care-package when i earn a sentry gun or sam turret. Things like juggernaut should have to come in a case. I do prefer the napalm to the predator missile.
"...and we'll see you tomorrow night!"