This is without abusing cavalry cheese instead using the germans and austrians to fight the french while their ally the english were having a tough time.
I'd say overall larger countries have become a lot stronger now in this patch and you can't 100% ignore society techs anymore due to how the whole local price system works. Which is good but I think quite a few don't know what exactly is happening so can be confusing for some. Also performance is noticeable early then there's a weird slow down around 1900s which then clears up again in the 20-30s
There's not that much I guess, migration has been nerfed so you won't have masses of people just moving across the entire globe, and market access price index is the big one that forces people to concentrate more on building vertical in certain provinces.