I think the larger ships (anything bigger than an ISD) should be more minor aspects of gameplay - the engine can't handle them, they can't really move around and with the unit cap they are hard to balance and reduce the variety in fleet composition.
SSDs should be a flagship-type unit - something unique which is only rarely seen. I don't like the factions being able to spam them like a normal unit. The AI can't use them properly to begin with - Zsinj must be drunk behind the wheel of his SSD, as it spends most of the battle randomly meandering around the jump-in point.
I can live with Battlecruisers - the Alliegance and Praetor are good counters for the VSD/ISD type ships while being rightfully vulnerable to bombers. Secutors and Lucrehulks are well-defined units with a role - maybe not completely balanced but they can fit on the map.
SSDs can basically zerg-rush almost anything. They have twice as much effective HP just due to overkill damage against destroyed hardpoints - that negates a lot of the weaknesses against volley-type attacks like bombers. Not to mention that they often have trouble getting to the battle to begin with - I just jump one into the middle of everything and let loose with the 1000+ turbolasers. Even if it takes damage, it is worth WAY more than 18 pop points before it goes down.
Call it the Thrawn doctrine.
That's the main reason I would love to see the entire roster of battlecruiser ship types before the remaining SSDs (Assertor and Mandator I think) even though SSDs are awesome in their own way, the battlecruisers are way more maneuverable and handled by the engine far better. They allow my fleet to have a solid anchor or powerful command ship that doesn't take up all of my pop points or 3/4 of the screen. Also, if we ever got the Praetor variant, unlikely as that is, it fills the same role as the Lucrehulk and secutor, but theoretically with more armour, which could be interesting.
I do like how, even though they all big command vessels, each SSD has some sort of unique role/strength. Assertors are there to deal massive firepower, Bellators are supposed to be the fastest, executors the biggest carrier/mobile command, Mandator is meant to take a beating and the Eclipse and Sovereign have those giant lasers of doom. I just find it interesting that they aren't complete carbon copies of each other, but each designed around a different main function, except maybe the Vengeance, other than being scary and black, it is just kind of an Executor with less fighters and overall mass.
I'm personally tempted to treat the Twilight mission Star Destroyer as being the same vessel later known as the Conqueror (destroyed, 1 ABY). I know the back-story for the latter implies it's post-Death Star but testbed to revived substitute terror weapon isn't too much of a stretch there.
That would make sense, and make for an interesting story of the Empire saying, "No, we never had a super-laser ship before . . ." shifty eyes, "This one is completely new"
On the topic of actual feedback about the Demo though, I don't know if this is a base game thing or because I am using 'More submod for Thrawn's revenge' but has anyone else noticed that Quasar ships get listed as casualties in almost every battle, despite usually not being present? I think I shall have to reinstall the Demo as just its vanilla form and test that.