The Avenger is a necessary evil. Even if it is expensive. Its one of the best Anti Air units in the game.
Yup, that damn Point Defence Lasers can't do a thing :D And Countermeasures don't work either. But Gatling Tanks are also verry good AA units (Don't forget the +25% Damage upgrade :))
Avengers can get 20% firepower bonus from Bombardment strategy plan
So?? That doesn't makes a real diference since they destroy any Aircraft that comes nearby, even without the Bombardement Strategy Plan... You should use Search and Destroy, which makes em fire further :D