Played some of the 1.9 patch and I have to say I like it. With the trade rework from 1.9 and the private economy rework from 1.7, the basic structure of the game's economy is how it should be, but it's a shame that it took them three years to get back to Vic2's baseline. It was so unbelievably retarded that for three full years after release trade was practically non-functional and every country had to be a self-reliant autarky. Playing as the USA now actually feels immersive since the South with their large export of cotton has significant influence. It's not quite there yet, but I could see with some refinement the tensions between the industrial North and the agrarian South being organically simulated. It's exciting, and it has the potential to not just equal Vic3 but surpass it (in the far, far future) due to the game's increased granularity.
It's now no longer a "HOI4 construction queue simulator". You can just be completely hands-off and let your capitalists decide what to build and trade. You still have a lot more control over your country's economy than in Vic2, however, since you can still manually build all buildings and decide their production methods, and set import/export tariffs/subventions on goods individually, rather than as a whole. I don't mind the increased control though, because player-directed construction, like an actual government, will always invariably distort the market and be less efficient than the investment pool which only seeks profit. Trade is the missing link that adds so much more richness to previously irrelevant mechanics like nationalization, subsidies, companies, etc.
Military however is still lame. They seem to be really stubborn about doing anything except returning back to manual control. You have all these levers like giving your soldiers better rations for +10% offense, or giving them flamethrowers for +10% morale damage or whatever, but all it is is just better economy = better army. You can set states as strategic objectives that the automated armies will prioritize conquering, but it's not all that relevant: who wins wars ultimately comes down to your economy. Choosing good states to target vs bad states has no impact. All their little gimmicks are just a way of avoiding the core issue which is that automated warfare can't represent properly the tactical advantages that countries like Prussia or the Confederacy had. The Union is heavily favored to win the Civil War in Vic3 due to its larger population and industry, as it should, but it wins in one year. There's no mechanic to represent the advantage that the CSA had.
AI's pretty passive as well, and the performance improvements from the new trade system aren't that significant, to me at least. All my performance problems with the newer PDX games could just be that I have an old machine from 2020, idk.