It seems like the Graviton Vulcan Cannon is the most advance weapon on the kinetic tree because it offers the best damage/mass ratio.
I finished researching the whole tree and I get:
Graviton Vulcan Cannon (13 damage / 3 mass = 4.333333333333333)
Quantum (15 damage / 5 mass = 3.0)
Singularity Driver (19 Damage / 5 mass = 3.8)
What does everyone else think? I am missing something here?