I'll pitch in wit my experience of Sylphon. I almost never buy the Dread Eagle because from my experiences, the Dread Eagle is a very vulnerable cruiser. The Scourge Eagle, less so, thanks to Outcast tech.
It's likely due to steady/aggressive captains going in with a strike/shock trooper-esque build and getting mauled by enemy ships because *warping right in front of them is the best course of action* logic.
The Dread Eagle, is incapable of "soloing entire fleets" unless their captains are either incompetent, poorly outfitted, wielding garbage fleets, or they have small ships. Taking on fleets that can very reliably fight back and have the tech to do so yields very different results, and you don't have to install mods for that either.
Now, issue addressed, Sylphon is unique thanks to nullspace, nulltech and AI core usage of the faction themselves. If my computer was more powerful, i'd play with this, Mikoyan, Blackrock and Shadowyards the whole time as well as other faction mods (such a fragile unit). They have varying ships with different roles revolving around nullspace. The Dread/Scourge Eagle are 1 or 2 examples of this. For a really good example, look at the remnant-esque capital, the Equilibrium and how it wields it's tech. Yes, it's a Nullspace Skimmer, but it doesn't need to warp behind to use it effectively. More so thanks to the hullmods. Seresvalla is a fleet support ship with a varying loadout that can be used to tell Conquests to "cease and desist", or drink the flux and blast enemies with it. It's not a ship that should be left to it's own devices from my experiences, even if it can have loadouts that allow it to.
The only ship I've a definitive problem with is the Gotter-gunner ship, the Finis Astra. A very specific niche is filled with that ship, which is otherwise useless, and that's station-killer duty. Other than that, the faction is solid, and it saddens me that some factors are leading to abandonment. I do hope the faction still gets maintained in the future, but it seems that all that's needed is some time off of working on Sylphon, no matter how long.