Heres what I think
The new levels on capital ship abilities is great, it really lets you specialize each cap to better fulfill what ever role you want it too.
Incoming wall of text on the new capital ship
I have mixed feelings on the new TEC battlecruiser. First off it looks like a cargo hauler, which is ok but I was just hoping that since its been decades (in game) it would be a new design specifically for combat (like the Kol) rather than another refitted civy vessel. As for its abilites, while they are fun to use, I'm not sure how useful they are going to be in actual competitive multiplayer.
The first ability Boarding Party (not sure on the name) is the ships signiture ability. It applies a damage over time that scales in duration and damage per second each level. If the target dies from any source while the effect is present the ship is healed for a significant amount and put under your control. It sounds great, but the cooldown is long, the range is shorter than the ships second ability (you'll see why i mention this in a second) and it can't target capitals and Titans. While I think the ability to caputer another players capital ship and or titan would be op, not being able to use this ability on them really cripples this ship in a capital ship fight.
The second ability sends a team to scuttle a target friendly vessel. If the vessel destroyed is one that you commandeered via boarding party the damage is increased by a decent amount. Using boarding party on a weakened enemy and then following up with this one is a lot of fun.
The third ability is a passive that restores some hull points to the battlecruiser when ever a friendly target dies. This bonus is boosted by a large amount if the ship that dies was one you commandeered via Boarding party.
The lvl 6 ability sends an elite crew to another ship to boost its effectiveness, increasing the targets weapon speed, shield regeneration and movement speed by a large amount (about 30% at lvl 1, around 60% at level 2). This abilty cannot be used on Titans (good call that would be crazy).
I think the new Capital is a decent mid game ship, its first and second ability do significant damage to clusters of enemy ships. I wouldn't get it first on a small map because its damage is outclassed by other capitals (such as the Kol and Sova) and its boarding party cannot target enemy capitals so it gets its butt handed to it by other caps. However if you are not worried about fighting your opponent early it can be a good choice, if you focus on stealing as many neutral ships as possible.
Overall I think its a gimmicky ship, although a cool one. If the range on Boarding Party is buffed and the cool down lowered slightly I think this ship will be fine.
I'm not really sure about Corvettes, I haven't really figured out how to use them effectively. I did figure out that mines completely annihilate them though, seriously its not even funny how hard they get countered by them.
As for the Titans, I prefer the loyalist one, once it has a few levels under its belt it is incredibly tough to kill while putting out good damage. The Rebel one is more of a Spellcaster/Sniper. I'd go into more detail but I only used them to comp stomp the AI. My initial impression is that the Loyalists got a much better deal.