I agree with others. I dont think it was meant to be somekind of an etirely NEW game. Its Dominions 2 with enough improvements to be Dominions 3.
I think that mainly we are entering a new era (oops, a pun since Dom3 introduces eras) in the games development. When Dom1 and Dom2 came out there were many player suggested improvements. And they got put in on a regular basis. Then each of them started developing a wishlist full of items which couldnt be put in without large rewrites to the way the game did things. When Johan got frustrated at getting more "cant do" than "can do" suggestions, he seems to start a new version
So even though there might not be a visible difference to you, I see it as a step that was needed so we could go forward. And I have no problem paying full-game price for that work.
On the other hand, Im thrilled with additions for solo play. Better AIs, more AI settings, larger maps, more random events, randomly generated maps.