I suggest following ;)
Because air tend to patrol in a constant line and not bulked, they are really weak against a bulk of vamps flying in at a single point.
Also ground AA has a too high range.
If you nerf Rapiers in range they are weaker than most other AA because:
1. They can get damage from Vamps and Avengers special AA missle.
2. They can be outranged by Vamps even now if you micro Vamps well.
3. The HP got nerfed from 1400 to 1300 ( Did they had 1500 at any time? )
I think that rapiers need to be more like Avengers - one AA weapon and one Ground weapon.
Even if you decide that it can use both weapons at once.
It would be a bit stronger against air than ground if it can attack air with it's ground weapon too.
( What's about a high range AA missle and a stronger ground missle witch can attack near fighters as well? )
To compensate this extended AA abilities the vamp can get more range - like a Archangel or more than that?
Vamps should be able to get slower while moving toward any possible target and get max speed if it is flying without deal damage.
That behavior would increase the chances of Vamps on Patrol because they can fly/turn faster while they are aiming at the attackers.
But it's also false that Avengers deal constant rates of damage !
Avengers can only attack the target efficiently with it's laser weapons.
But Vamp hit each possible target in the weapons angle while it can't fire at the primary target.
Also Vamp deals damage while it's getting closer in a constant rate, but never get close to the faster Avenger.
The faster speed of Avengers don't let them time to fire it's laser weapons as long as the Vamp.
The Vamp is flying behind an Avenger deals damage while the Avenger is getting away.
But I still don't understand why the Avenger with it's AA missle need this extreme fast turning moves.
Vamp need it much more than Avenger !!!