calvinms: contrary to most people say, I LOVE Homm 4. it's the only installment that allows your hero to combat in battle and once your hero is powerful enough, you dont need to build ton of armies. It's pretty satisfying + epic when you are finishing epic campaign by using a team that consisted all-star heroes.
That's the problem. Heroes of Might And Magic IV is a RPG, it's not a strategy game. The previous games were a nuclear arms race, it was all about hiring heroes, exploring, collecting resources, securing gold and important resource mines, buying units, conquering and holding vital castles... Battles were much more like chess where spells were used once per turn to change the dynamic of the battle and increase your odds of winning.
The fourth game instead is all about leveling heroes, learning spells, getting artifacts, accomplishing quests, not that any of these features were absent in the previous games, but in the previous games the focus was always on the strategy aspect, I don't recall building a party of wizards, teaching them as many damage spells as I could, then using them to blast every monsters and enemy heroes I could find while my creatures tanked the damage in the three first games (Excluding the Armageddon + Dragon/efreet missions in the first campaign of Restoration of Erathia), but in Heroes IV, it was a valid strategy, and I was very successful at it.
In the end it's all about that. If you like RPG, leveling heroes and finding artifacts, you'll love Heroes IV, if on the other hand what you like is the strategy aspect, the nuclear arms race and fighting for every inches of land, stealing others players' mines and castles, then Heroes II and III are still the games to beat.