Some observations from spending a couple hours with hive void dwellers yesterday (to 2265) and machine intelligence void dwellers (into the 2220s) today.
The number of raw resource or research districts you get is not clear at any point until the colonization process completes. You don't know how many you'll get when you choose to construct the habitat, nor even when you send a colony ship. I have been unpleasantly surprised several times. The tooltip on mousing-over a system now only shows you the max districts (consistently 9 to 13 for me).
Districts still cost alloy to build like they did in the beta. They also still have alloy upkeep. At least district and building upkeep reductions seem to be working correctly on them now.
The math on jobs from zones is very strange with habitats. With Void Dwellers, unspecialized raw resource districts are giving 150 jobs (vs 200 from raw resource districts on a planet). With specialization, that goes up to 300 for both. So we're no longer getting more jobs than planet-side districts; if anything we're getting fewer early and then coming up to parity. Similarly, getting a second specialization for city districts on normal planets comes from Colonial Centralization, a tier-2 society tech, while getting a second specialization for habitation districts is blocked on the upgraded habitats tech, which I finally got as my hive in 2265. While void dwellers are getting 150 jobs per habitation district from just the one specialization vs 100 at game start for planet-dwellers, planet-dwellers are getting the upgrade to 200 jobs per city district much, much earlier. I do appreciate being able to specialize most of my science into Engineering to help get that habitat upgrade out though.
The job efficiency bonus from the new version of the species trait is pretty good since it now stacks multiplicatively with lots of +% output modifiers. idk whether that's a big enough bonus to make up for fewer jobs per district.
I'm still feeling fairly squeezed for energy and relying heavily on solar panels and hydroponics bays. Habitats still have the problem they've had since the rework where you never get enough of either mining or generator districts to make it really worth specializing heavily in either, and still lack a rural designation. Several new factors put habitats at an additional comparative disadvantage for raw resource production: habitation districts can't select the Mining Support or Generator Support specializations (which would be perfect for eg a 10-district habitat with 6 max mining districts), and habitat mining/generator districts can't build the new +max districts buildings like Conductive Works Complex.
The research district specialization situation is also a bit weird, where on a regular planet you could do double engineering specialization on your city districts and only build the engineering support building, while a research district with engineering spec sticks you with a mix of scientist types plus some extra engineers (45 / 45 / 195), and then in the city slots you can only build Archives to support it. I guess ultimately 195 engineers plus 90 other jobs is kinda coming out ahead of 200 engineers for a double-spec'd city district though.
The planetary deficit / trade changes also seems like it hits habitats hard, since when you have lots of tiny planets, you're going to run lots of deficits. Maybe the best way to play habitats now is to build short, integrated supply chains on individual habitats. Sounds expensive in strategics for upgraded buildings, but at least refining seems very productive these days? Sadly habitat designations are still stuck in the days before the previous rework, with no support for mixed-use.
(or play Mercantile, megacorp, etc and just produce lots of trade rather than gestalts who don't get support buildings like Galactic Stock Exchange or a trade designation on their regular worlds, never mind habitats, I guess)