Well, you can't tell me all those worlds are actually memorable. You know what's in Corvus, Askonia, Magec, Aztlan, Valhalla-Ragnar, Eos Exodus, uhhh... Westernesse, Thule, Hybrasil... But the fact is that the more planets in the core there are, the more distinct they have to be or they risk being places that exist and maybe you even know it, but aren't ever relevant to you. At some point it's not more features, but more bloat. If Alex makes the core more interesting by having less boring stuff in it, good. I personally would ask only for uninhabited systems in the core have loot, danger or be possibly colonisable, even if that'd mean *** off other factions (perhaps that's why they're empty in the first space, because neither side wants to spark a total war).
By the way, Alex, have you thought about arms dealer mechanic to allow a player with some real estate to access military markets of other factions (those that agree to trade ships and weapons for something)?