If you're fan of CK2 then you should enjoy CK3. Some features have been removed such as merchant republics, but this will hopefully lead to a more clean implementation in CK3 when they add it (although probably as a DLC). It can feel a bit shallow at times but it's still a great game.
Has a few fun features, primarily trade companies. Being able to separate your trade capital from your real capital is really useful, but I feel like that sort of thing should be in the base game.
The content pack adds a lot of flavor when playing as one of the diadochi, a.k.a Alexander's successors. Something that isn't really mentioned anywhere is that legion dedications (basically buffs that lasts the whole game) can't be earned without the DLC.
The game is more polished and contains some more stuff than it's predecessor, but it feels like all addition could have just been added to the old one.
Overall, the two games aren't that different from each other, but if you don't own the first one, this is a good buy.
It's not a bad DLC for what it is, but it's mostly useless outside of colonizing and the New World. The nation designer is cool but not really a must-have feature, I personally never use it as I always play on ironman.
I'd say you should only get this if you want to play as natives or are really into colonizing. Get it when it's on sale as every other paradox DLC.
This is one of the better/useful EU4 DLCs (together with Rights of Man and Art of War). The best thing in the DLC is probably the age mechanic, which is really neat and adds a lot of new goals and bonuses during a playthrough, for all nations.
A lot of additional flavour is added to asian countries since all of them get affected by the changes to China and to a lesser extent Japan and Manchu.
This game is for either Borderlands fans or Telltale fans (or a combination).
For Borderlands fans it expands the game universe with additional history and "side-stories" to the main games, it also has the same sort of humor and style.
For Telltale fans it brings the top notch storytelling as those in The Walking Dead or The Wolf Among Us, with the same kind of gameplay.
Conclave has a few features that some people dislike, but those can be disabled nowadays. Overall though, I enjoyed the DLC and I recommend it to anyone who spends a lot of time on CK2.