So I did have a chance to try the game...
Well, its a lot harder to 'critically fail' yourself into a corner. There are a lot less hard checks and also a lot less 'hard checks'. There seems to be a way to get the better result no matter how you're equipped. More options for all characters, with the lifestyles. The stress mechanic is kind of nice, though the only time it really came into effect was with my 'shy' ruler. Things are a bit more transparent, you know how likely you are to fail, and you know roughly how well you can expect to do.
Vassals seem easy to please. Councilors have guaranteed outcomes that varies the amount of time rather than chance of success (ie: converting county takes X-years, instead of an X-chance per month to tick.) I feel like my personal playstyle had less agency than in CKII.
Sway seems really powerful. So is getting all these favors and hooks. Its excessive how much money I can squeeze out of .... everyone without pissing anyone at all off.
Wars were rather trivial in the heartlands of Christendom. Some wonk wrt the rng/alliances, but I rather liked how transparent the 'troop quality' 'retinue' and 'counter' systems work. I felt like all I really needed was to wait until somebody died or a rather bad war came around, then dow and win. Warscore ticks up in a nice fashion though. Wars dont feel exponentially prolonged like some wars in CKII can feel.
I dont like the way they portray baronies. Just do it the CKII way. I also dont like how I cant look at how people view other characters, such as who hates the Holy Roman Emperor or who [really] likes my wife. I like the hereditary system, and I kind of like how they did tech. There's some spartan options with micromanagement of things like how to get people to your court and how to raise local levies.
How is there no 'hard mode'? Otherwise, meh, there's definitely a game here, as is. Hopefully it does get better though.
P: My overarching thought is thusly: What if CKII had an 'Arcade Version'? Streamlined, new paint, flashy music, pretty lights, 'more accessible'? Thats what CKIII is.
Kind of like how I think of Rome: Total War as the arcade version of Rome: Total Realism, if that make sense.