Just played about eight hours of the new build. After I increased the build speeds and training rates the game got really fun and exciting. That was when I noticed some big problems with the current prestige system. I know we all want city spam to a minimum on medium sized maps and that this new system is a way to force a decision between a few large cities and several smaller ones. I also know that this change is making it impossible to to reasonably expand on a larger map.
You absolutely need to be able to have your influence cover every part of your territory. Otherwise any ally will send an army of pioneers into your territory and fill in the gaps. The argument would be that a properly functioning AI would never do that because its, well, dickish to steal an allies resources and create rifts in their territory. The AI is building too many pioneers and sends them everywhere. It just doesn't care about prestige. It only wants maximum territory. This cripples it by midgame where it can no longer increase its population, negating an level 4 or 5 benefits. It forces me to go to war with them, wipe them out... women and children too. Sure they are building actual armies now instead of soldiers and sure its a bit of a struggle to raze all those level 1 cities, but it really isn't hard to kill a kingdom that is that spread out. Its like the AI should have been for the Thalans in Galciv2 but that is another discussion.
Because the AI plays the aforementioned game, the human component is forced to counter with his own race to either place cities at choke points and never sign a damn treaty, declare total war, or make sure there are no gaps between any cities. The latter is impossible with prestige only working for about 5 cities and then dropping to .3 per turn in most places. I have reached a point where I have the territory i need for the endgame, but I have to wait 20 turns to get 20 people to build an inn to get .33 per turn in my capitol. This is bad gameplay.
There are many ways to fix this problem. You can ignore it, because I will surely mod the prestige factors if you are building this game for medium players only. You can get rid of the equation you are using and find a new way to regulate sprawl. You can wait until the AI is able to not sprawl and reassess the problem, but that won't be for months. You can factor in map size or even, gulp, make this an option that can be increased or decreased before a game. Finally, you can up the prestige values for all producing buildings by a factor of say 10 to 50 which will still give the desired effect you had envisioned, but with many more cities able to get to level 3 and up until the AI is fixed.
I am glad that we are finally to a point where these little things can be tested and refined. Great build guys.