Couple of things that I remember right now:
The weapons:
Small laser costs 2000. The pulse phaser cannon costs the same, but seems much stronger. The pulse plasma cannon costs 400 more but seems much weaker. The small phaser costs 2000 but again seems different in regards to its power lvl. Twin pulse phaser seems like it could outdo a large cannon. I didn't recognize any specific strengths or weaknesses of the weapons to reduce those differences in power in my tests.
Photon Torpedos are strong and relatively expensive, but their push power seems excessive. Everything that isn't gigantic gets pushed back and thrown like mad (this also looses them some of their power because most things will get pushed aside very far after the first contact making the others miss). The corner torpedo ones seem to give the ai some trouble, which is sad since I really like them.
Antiproton Gun, Antiproton Cannon and Antiproton Cannon 2: The cheaper variants can't compare with the pulse weapons and the cannon2 can't compare with the torpedos. I haven't tested those thoroughly though.
Added shields all seem to be very resilient and fast at reestablishing (Do they not have to charge fully before reestablishing?). Small shields are also extremely quick at reestablishing (They make my little fighters absolute beasts).
Generators also seem pretty good ( mostly tested the small one though).
Engines I don't really know about, hard to say. (Though with these and the space fuel generators I noticed some weird graphic effects).
Overall the power level of the added items seems pretty high. Most things I build with the mod could dispatch a significantly more expensive vanilla ship without breaking a sweat. Except when using things like the pulse plasma, I haven't killed anything with that yet.
On another note I've noticed that some pieces overlap (cut off) neighbouring parts a little or include slight traces of neighbouring parts that don't exist (I remember the fuel generators and some of the armor pieces from the top of my head).
Hope this was a bit helpful, just wrote down what I remembered from my last session. Thanks for your mod, this extension to the possibilities in cosmoteer is amazing 😃
One last thing, I really like non-gimbaled weapons, any plans for adding some of those?