I've always thought this upgrade is great. But it's completely overpriced. Sure it deals 400 DPS with good AOE. But it is nowhere as efficient as the Maser (Cybran ACU laser of death upgrade) with 4000 DPS! Yet, it costs around the same price (Maser costs 4000 mass / 500000 energy ; Sera weapon : 4500 mass / 300000 energy).
Moreover, the Sera ACU has to choose between the engineer suits 2 and 3 and this weapon. This is not the case for the Cybran ACU who can have both the engineer suits and laser of death (or torpedo upgrade).
That's why the chronotron amplifier has to have its costs extremely tuned down (and not just 5%). One of the Seraphim ACU game design goal is to be offensive (restoration field to heal the troops, Nano upgrades to heal the Acu on the front, super weapon). But this super weapon is just too expensive when you compare to the other ACU and what you need to sacrifice (engineer suits).
I think if the costs are halfed (mass and energy), we can have a worthy upgrade without being overpowered (even if it would still be really hard to forbid yourself the engineer suits) in order to have a fully offensive (and fearsome) ACU that is worth the gamble.
Thoughts?