I'll add some Japan feedback for a game on the latest unstable I completed a weekish ago: I do agree in previous versions it was pretty trivially easy to finish the tech tree as nearly anyone and that the increased tech costs makes it more of an actual achievement to finish a space race. However, Japan just has pretty poor modifiers in general which makes it hard to compete with already-established sprawling colonial empires. Yes, the UP does a good job catching you up, but when you actually need to be first to techs (ie, their third UHV) or, goodness forbid, try to complete a space race, it's a real struggle. Japan's inflation modifier and small core encourages you to stay pretty small for the majority of the game (in my experience it's infeasible to conquer anything beyond Korea and MAYBE a city or two in Manchuria before unlocking State Party), and then right as the tech goal starts to be really pressing, you have to do this mass conquest that crashes your economy for dozens and dozens of turns (on Marathon, even with State Party). I even made some power plays like GE rushing Bell Rock Lighthouse (the most powerful wonder in the late game), but it just wasn't enough. I think I got 4/8 Industrial techs before losing that goal after accomplishing the culture and conquest goal.
Not to say that I definitely played perfectly, but I was able to accomplish the UHV several times on the old map (it's one of my favorites). However, inflation and number of cities maintenance is just absolutely crushing in the newest versions... State Party is basically mandatory in the late game to have a functioning economy as most civs unless you stay small.
still was a fun game of course!
fairly quickly when you've got Renaissance free Libraries plus Versaille Estates.
