I would consider EU4 to be in a pretty good state. I can't talk to 1.6+ in particular, but 1.5.1 was pretty good, and actually even the initial release was in pretty good shape and fun. I patched EU3 to 5.2 from 5.1 last night, and played a bit of it, and it was hard to go back. EU3 5.2 also crashed, which I don't think I've had EU4 do one time. I recommend EU4 over EU3, and that's with no expansions for 4 and with all of them for 3.
Having played Saxony, you are going to get aggressive expansion by expanding aggressively. Vassalizing three countries in a war will likely get a coalition against you, although not necessarily with all your neighbors in it. Look for the diplomatic advisor who makes relations improve more quickly, and consider hiring him. I've about 80 years in and have 9 provinces, plus 9 more that are controlled by vassals or personal union partners. I generally expand by either one province or one vassal per war (and one vassal was added to the realm peacefully). There have been a few times a coalition has formed against me nonetheless. Although I went to war with the last coalition on purpose because it was three puny one province countries.
It can help to get alliances/vassals with your neighbors on one or more sides. Many of my neighbors are vassals/in a union, and another is an ally, so as long as I don't get both Bohemia and Austria in the coalition against me at the same time, they aren't very threatening.
For tech pointers/ideas, I guess it depends on what your goal is. The Diplomatic path is strong (though not necessary) if you want to pursue emperorship.
When you roll a new general (or admiral, conquistador, etc.) his stats are rolled, with higher army/navy tradition contributing to higher stats. Then the +1 leader stats from ideas are added.
AFAIK every stat can reach 6, but 6 siege is super rare.
Cool. I know in EU3, 2 siege was the max, but I think I saw some AI generals with more in my EU4 RTM game. Haven't looked carefully for that in my current one.
Any answers to how
Serfdom in the Aristocracy track works, and how I can verify I actually am getting more manpower?
What annoys me the most about 1.6 is that the Paradox forum looks like the WOW forums back in early Cataclysm. For those who do not know what that means a short explanation:
At the end of Wrath of the Lich king (the expansion prior to Cataclysm) powercreep had resulted in a powerlevel where players could clear 5 man dungeons without a full party, in some cases even without tanks or healers.
Once Cataclysm came along, however, everyone was naturally undergeared and so the 5 man dungeons from that expansion were (again) hard. But instead of adapting to the new situation by using crowd control effects or watch for positioning, players just kept whining "too hard! NERF! NERF!" until Blizzard gave in and nerfed the content.
The talk in the Pdox forums feels exactly like that. People whining how the game has become unplayable, but refusing to use tools that have been there from the very first day when the game was released. People demanding that you must be able to conquer half of the Ottomans in one war and no AI should care (and no, I am not exaggerating in this case). Instead of playing around a bit and trying to find a solution, the vocal minority cries "NERF! NERF!" in the forums and demands the QA/bet tester's heads on a pike.
A hotfix was released today, nerfing a lot of stuff - some things deserved, some (imho) not. Apart from that annoyance, 1.6 seems to work out nice, though. I enjoy the somewhat slower pace that requires a constant balance between expansion and integration. DIP cost for diplo annexing finally balances out that potential loophole and the overall changes (like the new build UI) are great.
The 100% increase in aggressive expansion meltaway in the patch did seem surprising, and quite large. Did they increase it in 1.6, or was that a major nerf? I thought the rate in 1.5.1 was pretty good. Although I was still a mid-sized country. Minimum revolt risk from nationalism being 20% of what nationalism add also seems a bit weaksauce, at least compared to EU3. I didn't play 1.6.0, and in 1.5.1 and earlier, nationalism was really easy to get rid of (make the province a core), so I can't really compare against earlier versions of EU4.