Thanks joncnunn.
So, unique districts:
-Build in 1/2 the time.
-Give unique bonuses.
-Don't count towards population requirements for other districts.
-Are able to host the same buildings as standard districts.
Very impressive. Unique improvements are nowhere near as good, in principle.
Wow, I wasn't aware of the third bullet - that's pretty impressive indeed.
By the way, what are the unique districts revealed so far?
- The Royal Dockyard (Harbor) for England
- Street Carnival (Entertainment) for Brazil
- Hansa (Commercial) for Germany
- Acropols (Theatre) for Greece
- Bath (Aqueduct) for (likely) Rome
This leaves me wondering if we see unique districts for some of the other unrevealed civs - I think at least Holy Site, Campus, Industrial and Military would be good candidates for replacements (unless Russia gets a Spaceport replacement).
Given that Arabia gets a building replacement, it is unlikely to also get a district replacement (although I suppose it would be a good candidate for a Holy Site replacement). Norway also gets the Stave Church.
So anyone wishes to speculate if Kongo, Russia or Sumeria gets any Unique District?
Edit: Also, doing some maths, with 18 civs (discounting Aztecs), 6 seem to be getting a unique improvement (China, Egypt, Scythia, France, India and Spain), 5 get a unique district (England, Rome, Greece, Germany and Brazil), and 4 unique buildings (America, Arabia, Norway and Japan).
If this is spread proportionally, then I suppose out of Kongo, Russia and Sumeria, we will get 1 more unique district and 2 unique buildings.