So I dropped it for the moment after my last game, which embodies the major problems I have with it as it is perfectly:
My first two campaign attempts this weekend seemed kind of shallow, so I challenged myself to be successful with Prussia while using as little of the game systems as possible. By 1850 I stopped after I had a perfectly happy NGF. I had looked at the journal, built up various factories, chosen some techs, opened and ended trade routes only when prompted by reports on shortages or inefficent trade routes, clicked in the diplomatic menu on improve relations with German minors and reacted to events with the default choice.
So yeah. My main complaint (next to the bad UI) is that the various game systems don't really interact with each other, they largely just run side by side.
The only one that truly matters seems to be the economic one. Which has two main aspects: an okayish city builder and the trade routes. The latter get a decent result if you cling closely to the prompts. But if you actually want to refine that, it quickly becomes the most annoying micro in any Paradox game (mainly because the informations are displayed so badly). Like Stack hunting, but in lists, not on the map. Overall the economic intervention is too direct for the time period IMO, but it is the one system that actually works and produces a game loop.
The political systems are fine in principle, but not so much in practice. It seems too easy to get a progressive society and the changes do not in fact matter all that much. Whether absolute monarchy or liberal democracy, politics handle the same, free market or communist, the economy handles the same. Nor do the political interests really impact the other parts of the games. No landowners demanding protective tarriffs, no liberals pushing for German unification, no indusrialists arguing for colonial markets. If you keep the various groups sort of content (where economic success alone seems to go a long way) nothing they do really matters.
Diplomacy is fairly bland. Not just because the political reality in involved countries plays little role, or their economic needs. The AI also does not really seems to know what its interests are. None of the German minors has an interest to preserve its independence - or at least demands politicial considerations. Attempts to unify Germany are ignored even by Austria. But a minor colonial war produces a world war, because suddenly Russia and the US take an interest what Sweden was doing in Africa. Add the limited actions one can take and what should be the core mechanic imo lacks in the fun department.
Surprisingly the army system did not bother me as much as I expected. I'd still like more control than the fronts give me (not least because the AI of your own armies sometimes self immolates), but I can now see where just managing different armies could be fun. If the game actually would let me, say through an army Organisator. But instead we get these feudal mobs following their Generals.
Then again , it may have helped my estimate of the war system that I had little interest in going for a war, because the diplomatic actions around it were so much of a chore with the unpredictable
AI.
I can see a lot of potential in this game, but seeing what could be done with it does not suffice to motivate me to keep playing what is there.