This discussion assumes that you got Manifold.
Firstly, let's start with a side-by-side screenshot of the two weapons side-by-side.
Mass: Nearly identical, with Manifold having a slight
edge on Vector
DPS: Manifold does 2-3x more than its listed DPS, so it's the clear winner hear.
Range: Manifold is also the clear winner with no minimum range.
Speed: Manifold, once again is the clear winner.
AoE: Vector wins out here, but this is the only place where it wins.
Spread: The Vector has none, but 20 degrees is fairly insignificant.
Fit time: It takes 2 days
to fit a Vector and only a little over 5 hours
for a Manifold.
Furthermore, the Infernal Vector can only be fit on Demon Corp ships.Conclusion: The Infernal Vector is a useless weapon and I wish I hadn't gotten a single one. Thus far, the only good weapon we've got out of the Aliens is the Repeating Polaron and maybe the Infernal Gatling (but Gatling's never been that good). @CM_Scarlett