Hey there, been a little while, but I finally had a chance to play some full games vs the hard AI with the new changes in place... sub pens, resource tweaking etc.
My initial impression is that I really enjoy the game when playing as the Axis. I like the re-balance with Siberia, which makes Russia a bit more reliable at the center. The sub pens are fun, and seem to encourage more naval builds on the European side of the board, while also giving Japan a bit more breathing room to spend for ground in Asia, since they can use the sub pens to help support their Pacific naval defense. For the minor Axis powers, Iraq and Iran feel a lot more relevant to the overall game, because of the oil exchange. Even if they aren't expanding overland, or producing much in the way of units, just keeping them alive feels important for the war effort, because they can send critical oil to the 3 major Axis powers.
I wish the Balkans, Finland and Thailand had the same thing going on. Right now their role for the team is sort of an inversion of Iraq/Iran's role. Balkans, Finland and Thailand are more of a drain on German/Italian/Japanese resources and they have to expand quite a bit before they have enough oil and steel to really function on their own. They also tend to checkerboard the map and move pretty far afield from their starting core, once Germany/Japan do all the can-opening. Personally I think it would be cooler if their role was more resource support oriented, where they send stuff to the big 3 on the Axis team via the exchange phase, rather than going on the march. The ability to trade steel in particular would be cool, since steel much more than oil, really puts the hard limit on what you can build in a given round. If Finland could send 1 steel to Germany, Balkans 1 steel to Germany or Italy, and Thailand send 1 steel to Japan, that would provide a lot more flexibility in a given round, especially when it comes to purchasing necessary transports, or the big ticket items like Carriers and Heavy Tanks.
Anyhow, that's my only real suggestion for the Axis side, to get Balkans, Finland, and Thailand into the resource exchange, with support for the big 3.
On the Allied side, I think the resource exchange for the minor powers is somewhat less engaging than it is for the Axis. The Big 5 for the Allies (UK, Russia, British-Colonies, British-India, and USA) are pretty fun to play on their own, but the others are a bit of a toss up. I'd say British-Colonies and British India are now enjoyable, since they have enough going on in the neighborhood to keep them busy, and with aid from the UK they can be even more effective.
For France it basically comes down to whether you are willing to sacrifice critical early PU's/resources from USA to give the French something to work with, and whether you want to try and prop up Normandy out the gate. I guess China is similar, its up to the USA whether they have a chance to make an impact in central Asia. In both cases though, it's kinda hard to see the PU's being used there over Russia (where they can stack up more) or just keeping it for USA builds or for production expansion in places like Morocco, Norway, Truk etc. China is a bit of a special case, since it's still pretty tough to prop them up, even if sending max aid. Not sure, but they might use a buff. For the most part though it seems to work fairly well as is with the USA aid. I think the other minor Allies are set up kind of backwards though.
What I mean is that, if you want to utilize the aid phase, the resources/PUs are flowing from where they are more useful to where they are less useful. So for example, to me it would make more sense that KNIL resources might go to ANZAC (or India maybe). Or ANZAC resources go to the British (or British-Colonies). Or Brazil's resources going to USA etc... rather than the other way round. Ideally each of these minors should have like 2 possible ways to send aid, so they'd have a more compelling gameplay choice to make each round. Again the ability to trade even 1 steel would be particularly interesting, since the resource is so scarce. But basically that's what I'd do to make all those minor Allies feel more significant to the team. There's really only so much that you can do with your units when playing as South Africa, or the Dutch, Anzac or Brazil and can feel a little repetitive, but if you could send some aid (even a small amount) up to the big dogs on the Allied side, then those extra few PU's/Resources might make a real difference in the over-all fight vs the Axis.
The only other thought I have right now for the Allies, is that it might be cool if they had something similar to what the Axis have received with those sub-pens, some kind of specialized production feature that continuously spams units of a given type. Except rather than subs I'd maybe consider something like transports for the USA/UK, so that their North America production is more relevant as the game goes on. Or maybe you could try it with light Tanks, for something that Russia could make use of. I guess for simplicity it would probably make sense to just choose one unit type to highlight the way the Axis have subs. Probably Tanks would be the most fun, since the Western Allies kind of have the opposite problem as the Axis, they usually invest a lot in naval power, and somewhat less on heavy ground. I don't know, maybe its not necessary. Seemed like it was worth bringing up though just for parity by sides, since those sub pens can be pretty powerful after some time has elapsed. If the Allies are trying to match them round for round with destroyers, that's a lot of steel not being spent on tanks hehe.
Anyhow that's what I got for the moment. Will post some saves when I get home from work a little later. Still my favorite game for the AI I think