Wow -- just wow!
I have been stalking the progress of this mod for months, and finally checked and found it was released. Worked through the missing curry file with no problem. Thanks a million to everyone who's worked on it!!
Balance seems generally good. Surprisingly good. I played as Fed against both Feds and Klingons -- some of them on Hard, some on Unfair. Repelling huge enemy fleets wasn't too bad -- at one point I scared away the losing half of an enemy assault containing 68x Steamrunner, 37x Excelsior, 3x Galaxy. Only lost like 2x Akira and a Beam Defense Platform.
On the other hand, assaulting enemy sectors after the first few minutes of the game becomes prohibitively hard. The AI will spend the ridiculously high cost to upgrade their starbase defenses, which gave the enemy Fed starbases about 152k shields and 38k hitpoints!
At one point I decided to try and kill one. I researched ALL tech in all three branches, got max supply and max cap ships, then built a fleet of 16x Sovereign and 79x Akira.
My first task in assaulting their sector was to eliminate the standing fleet. For this sector it was surprisingly weak -- they only had about a dozen Akiras, a few non-Sovereign capitals, a dozen Steamrunners and a few beam defense platforms. After about a 15 minute battle I had cleared the sector of everything but the starbase and it only cost me 3 Akiras and an average of 75% shield status across all my ships.
Now the fun starts. I had all of my Akiras and Sovereigns attack the starbase at once. It was insanely hard. After about 30 minutes, I had 36x Akira and all of my Sovereigns remaining -- and that's after I replaced about 10 Akiras with rebuilt ones from my frigate factory in the adjacent sector. So the starbase destroyed about 50 Akiras and the remaining ships were all heavily or moderately damaged.
Is this intended? Is there supposed to be a quicker, less costly way to destroy starbases? The Solanus Adjudicator doesn't seem to be the solution, since they are fairly fragile and go down way quicker than Akiras -- plus it seems the Akira's torps do more damage anyway.
If this is the intended amount of effort it takes to destroy a maxed starbase, I have to say, it's epic -- and I like it. But I could never play SOA2 multiplayer in its current state. It just takes too much mental energy to conquer even a single sector, when I have to fully max out my fleet, then lose over half of it just destroying a starbase. And the amount of time it takes is a bit too slow for my tolerances.
The only way I could play SOA2 in its current state is by loading up the game, playing for 5 - 6 hours to conquer maybe 2 - 3 sectors, then save and come back the next day to chip away at the enemy some more. But I think if I did this for the time it takes to win a Large or Huge map, I would be sick of seeing Star Trek ships entirely. 
Basically the only thing interfering with what seems to be a well-balanced game is the durability of starbases. Their damage output is fine, but if they went down quicker, I would have to spend less time watching it slowly pick away at my massive fleet, and less time waiting for my shipyards to slowly replenish said fleet after the fight.
It'd be interesting to have an anti-starbase cap ship, but I'm not sure if any fit into the Trek universe, except maybe Species 8472's ships that destroyed an entire planet in one volley 