For small mounts, energy weapons are generally terrible. The only ones that are useful are beams, and that is only for anti-missile or anti-small ship. (Occasionally, AM blaster is useful for overloading AI due to its terribly predictable flux management.) Ballistics, on the other hand, have gems like railgun and light needler. Even the crummy light (dual) AC and LAG beats the more expensive IR pulse laser.
For medium mounts, heavy blaster is great, and is probably one of the few energy weapons that can compete with the best ballistics. Phase Lance is great *IF* you have both Advanced Optics and other weapons that hit for hard flux.
For heavy mounts, Mjolnir outclasses all heavy energy weapons at overall performance.
In the next version, non-missile shots that fade out before hitting shields do soft-flux only. This will hurt energy weapons more.
Well, guys, lets not forget high tech ships tend to be much faster, have superior flux stats, and most come with greatly superior shields.
For frigates, I agree. Lasher is one of the weakest ships in the game, and the other low-tech frigates are hybrids, and midline frigates are specialists. For destroyers and capitals, low-tech and high-tech are about on par with each other, and midline is weak. For cruisers, low-tech is excellent (especially Dominator), midline is good, and high-tech have somewhat underpowered specialists (Apogee for hybrid, Aurora for missiles, and Doom for strike).
As for the ammo thing, in vanilla Starsector, VERY few battles last long enough that you start to run out of important ammo.
As someone who chains lone flagships until level 50+, I definitely ran out of ammo frequently if I did not use energy weapons before ammo became unlimited. Now that most weapons do not use ammo anymore, I sometimes use Enforcer or Sunder over Medusa, and I usually use Dominator or Eagle over the high-tech cruisers.
Also, while the flux boost is gone, energy weapons got a static DPS boost to compensate. In some cases (plasma cannon) its a little short, but for most things it works.
Pulse lasers and heavy blaster made out. AM blaster, mining blaster, and plasma cannon got shafted. Beams did not get any damage boost, but cost less OP and some got more range. PD laser made LR PD laser obsolete. Burst PD is overpriced. Tactical laser is very good.