Inspired by a similar post in DA, here's a rundown of SRA weapons I've used so far:
light cepc
horrible as pd, good as a short-range weapon, especially in batteries or on pursuit craft. the light cepc could possibly benefit from turning it into a shotgun-type weapon, or simply increasing projectile speed and accuracy.
cepc/medium cepc
similar performance or slightly worse than vanilla weapons. becomes better than vanilla with expanded magazines. good versus armor.
scatter cepc
probably the best one of the lot. negligible flux cost, great damage, great versus all targets. deceptively good versus armor and exposed hull. could probably use a nerf.
chaingang cepc
lackluster compared to scatter cepc. while not useful as a means of pd, the rate of fire makes it somewhat useful on destroyers or pursuit craft, usually in corvus mode where you can't always get a scatter cepc.
tusk torpedo
good against all targets. their tracking and shotgun effect make them almost an auto-include on ships that can fit them. more useful for finishing off overloaded or venting ships than for causing overloads.
Spoiler
"Noooo. I've venting! Oh, what a world, what a world!"
urumi
passable if you can afford the op. early game, or on tight fits, it's better to stick with a cheaper method of pd.
trishula
while good for prolonged standoffs, as sra you should be avoiding those in the first place. somewhat flux inefficient.
shrike asm
will often miss a fast narrow target, somewhat useful if hunting destroyers with frigates. low op cost but inferior to tusks.
splinter
less useful than tusks, low op cost seems to be it's only redeeming quality.
blackcap
since playing against fighters groups is almost always an auto-win, i had no need for these. also, tusks.
That about covers it. Still haven't used most of the large sra ships and weapons, mainly because I find large fleet battles tedious. Besides the scatter cepc being overpowered (try putting two on a tempest), I haven't found any obvious imbalances. SRA does have a distinct playstyle different from vanilla, but as long as you stick to it the weapons are in no way underpowered.