Since the focus of the game is on hording and land grabbing (and has been for quite some time), I feel as though there should be roughly a 4000% increase in ack. This will at least add a modicum of challenge to the lemming hordes as they move from base to undefended base.
I also think that mannable SAM batteries might be a good idea, as well as mannable ack towers with 25 to 30 guns slaved together (sort of like buff boxes).