@KateMicucci
Good simply means: More worth using (a combination of damage, DPS and cost efficiency) than light weapons of the same tier.
Ramjets have less damage (and benefit less from +Acc since they have higher native acc than most light weapons), they do have better DPS but they also have an insane cost/damage (22k/shot, really? That's on par with Seagulls and...
Plasma Bombs)
In the early game, 50mm are more than enough to down most targets and really cheap to produce ammo for (10x! cheaper than Ramjets, for 1/2 the DPS and +50% total damage). The first decent heavy to me would be 105MM Rockets (bit more DPS, bit more total damage and much cheaper to produce than buying ramjet ammo). The first good heavy is the Naval Gun, then the Rail Gun. Unless there's a revamp coming on combat, Beam lasers are useless against military ships, so maybe build a few for intercepting non-shielded shipping, but keep most of your parts for Rail Guns as those will do the work you need them to against shielded targets.
@ohartenstein23
Yeah, I know, rail guns are where it's at. And I guess you're right that they are what you need in that period. I just fell for the beam laser before shields were used so I have no more power couplings and my experience is skewed. I'm now going back tech-wise and building Naval Guns to tackle cruisers
@legionof1
Yup, I'm not a fan of the codex thing either.