My opinion: Well, firstly, I'm happy that you still can choose 3 killstreaks. It would have been annoying, if you could use all of them at once.
But an annoying part is.. AC130 and the chopper gunner. It looks like that it is impossible to get those down.
Wont it be annoying, when you just start playing, and after 2 secs you die. Then you start again and then.. DEAD.
I don't think it will be that hard to be honest. Yes it will be annoying but for the chopper it will be one missile shot and a few gun shots and it will go down; and the AC-130 will take two missile shots max to shoot down.
I think that the killstreaks will be amazing.
Yes, you have to chose three to have, but I believe you can choose what order you unlock them in (AC130 before care package, etc).
I'm thinking UAV, Pave Low/AC130 and EMP. I'll have a play around first though and see what I like.
And all the missiles should make short work of some of the air support.