I'm only a few hours in.
Biggest difference imho is that you can't freely decide where to build your cities. There are predefined "city cites". I don't know yet if I like it or not.
Also you now manage your character, family and court. Similar to Crusader Kings, but much more shallow. I think that's a nice addition.
Haven't figured out city building yet, so why and when my borders grow and why or why not the city gathers ressources.
Maybe after you sink some more hours into it