Now I will begin by saying that I have played almost every TW game up to date and generally enjoyed them all even though they all follow the same pattern to a degree.
Secondly while I do not think I am super hardcore into lore of WH, I can definitely tell that CA has put a lot of effort into this just based on the models, interactions and lines your heroes/lords are saying.
While I played first Warhammer Total War and thought it was a very good game, I somehow let this one slide off my radar and the fact that I had this in library while not realizing it is nothing short of blasphemous. I suppose that's a result of more and more steam users having several hundreds and even thousands of games in library. Anyway fast forward to the latest sale, I realize I have this gem, get all the DLCs and start jamming a coop campaign with my wife. We still haven't finished our playthrough with Vampire Pirates and it's been already over 50 hours.
Visually, game looks stunning and I often find myself looking at the various monuments and details put into different areas of this somewhat "small" map. Fights can be breathtaking especially with the inclusion of various monsters and fliers this game has which simply breaks this somewhat dull pattern pure historical TW games have. Faction diversity is off the charts and they are not merely reskins but instead play completely differently. Even the same factions have different lords which greatly affect how the game is being played. Really cannot think of any other game with remotely this depth. I haven't even scratched the surface with over 50 hours in. DLCs are vast and while they are pricey, they even add more depth.
As for cons, I would say that diplomacy is very rudimentary at least when compared to grand strategy games such as Paradox Interactive titles and AI sometimes makes weird decisions but nothing too much off.
Definitely pick it when you get the chance, easily 9.5 out 10.