Quite a big disappointment, and for quite a few reasons.
The most glaring one is the price compared to the product. I waited for a sale to get it alongside the biggest DLC to date (with more planned out already and incoming). On sale with the DLC it was almost the price of a full AAA game. However it does not have the scale of that kind of game. It is a big one, for sure, but not due to content, but rather thanks to repetitiveness of what is in it. It is a re-hash of Planetfall and AoW 3 but with downgrades all around. In short, if you want a more honest return of your money, play Planetfall if you want a more modern AoW and don't mind the SF setting, or just stay with AoW 3.
The game biggest selling point with the "build-your-own-race" is almost a gimmick. You pick a template that has 2-3 defining quirks, choose the look and done. The rest is modified by your ruler spells, which can change your race into zombies, rock elementals etc. Overall good idea, but gets boring quickly, cause the differences are rather small and hold little significance.
The combat is what it used to be, no changes there it is copy-pasted from Planetfall, but with less interesting units.
The spell tomes at first seem great, but you quickly realise that they are almost all the same, but adhere to a different element, so you get the same spell, but it enhances with fire, and not ice and the same thing 10 times. On some occasions it gets more creative, with some spells being able to destroy mountains, but it seems like a rarity.
The late game does offer some more interesting buildings, spells and units, but it crashes due to a big, big problem. The time it takes the computer to take a turn. Even when you speed up all the animations, late game on a big map with 6 opponents, takes 1-2 minutes to give you your turn. Total War Warhammer 3, at the start of a new campaign has more than 200 factions and takes 10-15 seconds to give you your turn. It makes it unplayable to me, cause it bloats the playtime insufferably, specially given the scum tactics AI takes alongside cheating it uses on higher difficulty settings.
The story of the main campaign is non-existing, they did not pay any attention to it and relayed solely on replayability due to the customization systems of lords and races. The idea of the pantheon, where all the lords and races you created exist and can be seen as AI in later games is really good. Some other ideas are also really good. They are just realised poorly, or half-baked and then sold as a full game, that has 4 big DLCS planned out and in works before the full game released. This is Paradox strategy for a long time now and it sucks, cause it is probably the driving force behding Triumph Studios not really evolving their franchise. The whole game could be done as a mod for AoW3 and it would be better for it cause of a better core game.