Feedback time!
The following testing was done with a stripped Mimir, no hull mods, vents, capacitors or skills whatsoever
3 Deva beams for the large slots, fan Pd for the small ones, no mediums, rockets or use of the lance.
The testing subjects were various ships and fighters from vanilla and SS+ ( the mod itself, no auxiliary factions).
The fan Pd guns were a bit of an oddball for me, even thou they were easily capable of tracking fighters they seemed to be better at causing burnouts than causing much damage very quick, thou that wasn't much of an issue as they would collide against my shields then.
Shielded fighters can be a bit of a nuisance as the burst nature of the fan PD doesn't put enough pressure to cause an overload ( a thing even more obvious against the high tech family), but all it takes is for them to pass over you to get a shot in the rear and caput.
Anti missile capabilities are very good, solitary or small groups of missiles have little chances of getting through (unless they are very fast, like Sabot) but Salamanders and Piliums can suck it. Torpedoes also have little hopes unless they're fast.
Moving on to da big boyz.
Three Deva beams are unforgiving, both for player and enemy, one full burst from all 3 will raise your flux level from 0 to around 50% in an instant, cautious use is paramount.
That being said they are VERY strong against non high tech frigs and destroyers ( one burst can be enough to overload/seriously affect/destroy your average Enforcer, Vanguard, Hammerhead etc). But hey, they're LARGE burst weapons, kinda expected.
However, their pwnage fades against cruisers and caps, (even more so if high tech) forcing you think very carefully about when/where to shoot. Not to mention the generated flux can screw you over in a hearth beat.
One example is against a Barbarian, full burst will raise its flux to 95%, while against an Aurora it will only be at about 60%.
Against a Dominator 60% against a Zenith 40%. (again, this is expected against such opponents)
The long recharge and mediocre range further keep you from going on a power craze.
My final conclusion is that the new weapons don't need any further rebalancing. Good additions all around.