I mostly agree, but the fact is that Banshees, especially linked Banshees, are painfully slow firing(worse than the Prom-S), so unless you're a extremely consistent shot, you may well be shooting yourself in the foot and giving the enemy time to recharge/rebalance shields between hits. It just doesn't feel "worth it", especially considering the lack of damage against hulls.
The Avenger is just better balanced overall(along with the speed-accuracy bonus over the Prom), and the fact that it has no real drain on your gun energy doesn't hurt, either.
EDIT: And honestly, FS1 primaries really were more rapid-fire, damage-over-time guns as a whole, rather than the heavier damage per-shot guns that the Prom-S and Kayser arguably are(which goes right back to my first post, and how the game style has arguably changed from FS1 to 2, and thus fighter capabilities relative to the game).