After playing some more with bigger ship classes I can offer a few more of my experiences.
There are a few factions in the realm of "Heavy hitting, low mobility", such as II, THI, NGO and so forth, and PBC fit well into that category with a few twists. They do have some real powerhouses in terms of firepower, such as the Phobos and capitals, but they are even more easily overwhelmed than the THI and II ships of the same class due to their complete inability to disengage - even slowly. Despite this, they have very low OP points available for their class. On average the PBC destroyers for example have as much as 30-40 OP points less than their peers, despite similar mobility, shields and so forth, but then more weaknesses such as their exposure to missiles and rear attacks, and poorer arc coverage.
I have found that whilst the Moros and Phobos can trade fire with capital ships, they are often considered a threat and are too slow to catch other ships. Whilst the idea of stasis beams are sound, and they do work if you can break down an enemy's shields, it is very hard to make them practical in a fleet engagement. If you are travelling at speed 30 and your target ship is backing away from you, rarely will you be able to stay in range hitting its shields, and then be able to catch it in range to slow it down with the stasis beams.
The EMP ships such as the Aether and Aura are great fun, definitely my favourite in the mod, and I think there is definitely room for a more agile frigate for chasing, and another cruiser or a capital that can be a more interesting flag ship (i.e. similar firepower to the Phobos/Moros that can still be nimble, either through a ship system, or more OP or something). Aura is exceptionally weak for how close to danger they have to fly though so unless its early game and I am piloting it, I don't use them.
The plethora of specialised ships at this stage (Nyx, Aura, Aether, Orion, Pallas, Tethys) compared to the low(ish) number of ship types, hurts the PBC in fleet engagements. I think some more destroyers and cruisers could be added to compensate for PBC weaknesses somewhat for large engagements, where frigates don't really belong as pure PD boats. It also means that all of the above ships are only really useful if player-controlled, but then it leaves the heavy hitters that can only keep up so much, to be blundering around in AI-control.
Moros' ship system is very strong, and having limited charges balances this fact as you can weather the storm of the enemy's capital and then unleash your own against it. However, I feel the Moros would be better served with a mobility ship system such as a burn drive type, allowing it to use its broadside ability. Either that, or extending the arcs of the weapon mounts to cover the front as well, because it cannot keep up with targets, and so its broadsides rarely get brought into the equation. Another possible solution could be to make the shield frontal, so that attempting to flank a ship could be more rewarding, rather than exposing all of the firing weapons to enemy EMP etc.
I don't really use fighters and carriers so much but it seems as though the carrier options in this mod are quite lacking so far (I know, WIP), and perhaps the Gaia could have a flight deck added? It doesn't seem to be very worthwhile in my fleet and tends to die even when I ask it to sit back with the Aidos.
My experience with the mod-specific weapons has been quite low so far, so I will try to use them more to give some feedback on balance. Hopefully there is a good PD weapon on the way because at the moment, being slow & having engines exposed & having very low PD covering mounts means that missiles are exceptionally strong against the PBC.
Edit-
Some minor quality of life things that I have noticed:
- The Moros doesn't display weapon flux for me in the editor, but does in weapon groups
- AI Pallas uses its ship system even when travelling - could be a vanilla thing so not sure if it has an awareness of when to use it