With the playthrough finished, some more wonders thoughts:
- Metropolitain is very strong, especially for how early it comes. In a supercity, it's just categorically better than the Empire State Building, which comes later in the tech tree (see below screenshot for the effects of both in Berlin). I didn't build it as it comes far in the future, but comparing the Metropolitain's bonus to the Oriental Pearl Tower at the below screenshot and to Berlin's size again shows how strong the wonder is compared to the other 'supercity wonders' (Oriental Pearl would give 25 x 2 = 50 beakers, which is equal to the 50 commerce of Metropolitain, when Berlin isn't even fully infrastructured. It is likely that the two would break even at a fully populated and developed city, but Metropolitain comes far earlier. If the screenshotted Berlin is fully developed w/o any additional variables, it can reach size 27 with slight starvation, and build an additional ten buildings to get to 35 buildings. Oriental Pearl would give 54 beakers, and Metropolitain 70 commerce.).
- The Palace of Nations has a really fun effect, but the Congresses it triggered all turned into duds with no request opportunities. This may have been because I (who built the thing) was almost always at war.
- I didn't have the chance to build them before the game's end, but Gardens by the Bay and Harbour Opera both seem a bit weak, especially compared to the aforementioned Metropolitain. Harbour Opera may be worth its input, but it comes so late that it may not pay off, and it could actually be obscenely broken if stacked with some other wonders (Emerald Buddha Temple and the National Theatre in particular come to mind).
- Hubble Space Telescope is a strictly better wonder than the Large Hadron Collider (not accounting for the tech paths). They cost the same number of hammers and give the same research modifier and GPP, but Hubble does not require a Laboratory to build and also gives culture, while the LHC does not.
- Crystal Cathedral has two fun effects, but the numbers feel too weak. Pumping them to 1 Happiness / 15% gold (if this is possible) and/or +2 Commerce per priest wouldn't be ridiculously broken, I think, particularly given the rarity of Priests as specialists in the late game.
- Golden Gate Bridge (aside from the aforementioned bug) is a good wonder that feels really great to build: it costs an appropriate amount of hammers for its effect, and its effect can really be felt when built by any of the late game civs (Japan, Prussia, USA) who tend to spam Engineer/Scientist in their cities. I imagine the Skytree would have a similar feeling upon being built, but it comes rather late, and would also be obscene if combined with Golden Gate.
Lastly, some screenshots to show both the aforementioned strength of the Metropolitain (and some wonder spamming in Berlin), and the wonder spread for the lategame. Note that these were taken a turn after the completion of the Prussian UHV, so obviously all of Europe is under the German yoke and that reflects in the ownership of wonders. The important bit is that this shows how concentrated wonder construction was in Europe, and furthermore, I built most of the wonders, not conquered them. In general, I think the late game wonders are really fun to play with for the most part; there's just a few outliers as far as wonder strength that hearken back to vanilla BtS Pyramids in how transformative they can be.