There are a few World Wonders that I'm still not happy with as far as their effects go. I am not about to actually change anything right now. I am more concerned with getting all the graphics changes in place. When I do that, it's now or never since it's going to be big. Once the graphics are in place, then I want to round up any last changes and bring my work pretty much to a close.
Here are the Wonders I am thinking about changing:
Silk Road
A mix of boring and overpowered in its current format. It generates a lot of gold but that is all it does. First of all, I would prefer it moved to Calendar AND Aristocracy and fold the Silk Farm back into Plantation. I don't see why Silk should be treated differently from other Plantation-requiring resources and I don't like having single-resource improvements. I can handle them if they are late-game and strategic resources like the Well, but not early-game improvements and not luxuries.
I have Python code that would turn Silk Road into a real road; lay roads connecting the building city to all sources of Silk in your territory, then to your Capital, and then to the largest city on the map that you have seen. It might be good to use that and a foreign commerce bonus instead of the big gold bonus.
Copernicus' Observatory and Leonardo's Workshop
These desperately need to be differentiated. Copernicus is close to a Cathedral-class building, not a National Wonder and certainly not a World Wonder, so it needs something. 1 free tech is off-limits, though: that's limited to Oracle, Cheomseongdae, and Computer Center.
I'm thinking of making Leonardo a jack-of-all-trades; delete the Science bonus completely just so that it is different from Copernicus and Newton, but add +1 culture per specialist and -25% cost to upgrade units. Art of War is the only Wonder that does this right now.
Reichstag
I've been convinced this is overpowered in its current format. I couldn't make the check for only 1 Golden Age per civilization work. I think to restrain this, I can limit the Golden Age to 1 turn per city of the rival (scaled by game speed, but can't display this in the help text) AND prevent the Golden Age from triggering if the player is already in Golden Age status.
Women's Suffrage
Again, this is a dull Wonder. It has the same effect as Mt. Rushmore (although it does stack). I'm speculating on shuffling around Cristo Redentor's No Anarchy and Statue of Liberty's free Specialists around with Women's Suffrage to make them fit better. This just occurred to me, so I haven't thought it through completely.
A lot of this is musing on my part, but I want Wonders to feel like they are worth the effort to build.