I am doing Ivan's campaign now. So far I really like H7 and think it has made many improvements - in UI (e.g. two clicks to restart a battle) and of course in 3D maps. No skill reset is bad news, though.
The biggest "beef" I have in terms of campaign gameplay is that the AI opponent, in certain maps, unleashes quite powerful, main AI heroes straight to get our main hero early game, and after defeating that invasion, the AI has no more (significant) troops and the game becomes quite boring. The difficulty curve needs some work. I know as a human player I would totally crush my opponent in its infancy

And I don't enjoy the maps with time limit as I couldn't explore the whole map, getting all stat boosts, etc. Well even if I had, many heroes just don't carry over. What a disappointment! And the "main" academy hero's skills get reset between M1 and M4! What an insult to the campaign!