After the release of the fourth game, I only had positive impressions – the hero's participation in battles, the new hero development system (I won't say whether it's better or worse, but new things are always more interesting to me than old ones), and even those features that practically no one likes appealed to me – monsters without upgrades (because you don't need to occupy extra stacks for upgraded and non-upgraded troops) and the simultaneous attack of attacking and defending troops (because, in my opinion, this makes battles more complex and diversifies tactics). In general, for quite a long time (until the release of the fifth game), I considered it the best game in the series.
Now I consider the fifth game to be the best, because, in my opinion, it incorporates many of the best features from both the third (and second) and fourth games. And in general, I like everything new.